Display System, Display Device, and Light-Emitting Apparatus

ABSTRACT

A highly convenient display system is provided. A display system that enables a screen to be operated easily with a laser pointer is provided. A display system that enables a screen to be operated by a large number of people is provided. The display system includes a light-emitting apparatus and a display device. The light-emitting apparatus includes a means for emitting visible laser light and a means for emitting invisible light. The display device includes a display unit including a means for displaying an image and a means for obtaining positional information on a portion irradiated with the visible light, and a means for receiving the invisible light. The display system has a function of performing processing in accordance with the positional information when the invisible light is received.

This application is a continuation of copending U.S. application Ser.No. 17/422,891, filed on Jul. 14, 2021 which is a 371 of internationalapplication PCT/IB2020/050067 filed on Jan. 7, 2020 which are allincorporated herein by reference.

TECHNICAL FIELD

One embodiment of the present invention relates to a display system. Oneembodiment of the present invention relates to a display device. Oneembodiment of the present invention relates to an input device. Oneembodiment of the present invention relates to a light-emittingapparatus.

Note that one embodiment of the present invention is not limited to theabove technical field. Examples of the technical field of one embodimentof the present invention disclosed in this specification and the likeinclude a semiconductor device, a display device, a light-emittingapparatus, a power storage device, a memory device, an electronicdevice, a lighting device, an input device, an input/output device, adriving method thereof, and a manufacturing method thereof. Asemiconductor device generally means a device that can function byutilizing semiconductor characteristics.

BACKGROUND ART

In recent years, larger-sized display devices have been manufactured.Examples of uses for a large-sized display device include a televisiondevice for home use (also referred to as a TV or a television receiver),digital signage, and a PID (Public Information Display).

Light-emitting apparatuses including light-emitting elements have beendeveloped, for example, as display devices. Light-emitting elements(also referred to as EL elements) utilizing an electroluminescence(hereinafter referred to as EL) phenomenon have features such as ease ofreduction in thickness and weight, high-speed response to an inputsignal, and driving with a direct-current low voltage source, and havebeen used in display devices. For example, Patent Document 1 discloses aflexible light-emitting apparatus including an organic EL element.

REFERENCE Patent Document

-   [Patent Document 1] Japanese Published Patent Application No.    2014-197522

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

With the size of a display device being increased, the screen can beseen by a large number of people. For display devices to be used forpresentations, multiplayer games at an amusement facility, or the like,the display devices are required not only to be viewed but also to beoperated.

A laser pointer, which is often used for presentations at a meeting, forexample, is capable of pointing a portion where a user pays attention,but is not capable of operating a screen. Thus, the user making thepresentations need to do two actions simultaneously, i.e., making thepresentations while pointing a laser pointer at the screen and operatingthe screen with a mouse or a controller, which hinders the user fromgiving presentations smoothly. In addition, users other than the onemaking the presentations are unable to operate the screen.

An object of one embodiment of the present invention is to provide ahighly convenient display system. Another object is to provide a displaysystem enabling a screen to be operated easily with a laser pointer.Another object is to provide a display system enabling a screen to beoperated by a large number of people. Another object is to provide adisplay device and a laser pointer device (a light-emitting apparatus)enabling the above display system. Another object is to provide adisplay device capable of obtaining positional information on a portionpointed by a laser pointer. Another object is to provide a devicecapable of operating a screen, which replaces a conventional laserpointer.

Another object of one embodiment of the present invention is to providea display device with a reduced manufacturing cost. Another object is toprovide a high-quality display device, light-emitting apparatus ordisplay system. Another object is to provide a highly reliable displaydevice, light-emitting apparatus, or display system. Another object isto provide a novel display device, light-emitting apparatus, or displaysystem.

Note that the description of these objects does not preclude theexistence of other objects. One embodiment of the present invention doesnot have to achieve all these objects. Note that objects other thanthese can be derived from the description of the specification, thedrawings, the claims, and the like.

Means for Solving the Problems

One embodiment of the present invention is a display system including adisplay device and a light-emitting apparatus. The light-emittingapparatus includes a means for emitting visible light and a means foremitting invisible light. The display device includes a display unitincluding a means for displaying an image and a means for obtainingpositional information on a portion irradiated with the visible light,and a means for receiving the invisible light.

Another embodiment of the present invention is a display systemincluding a display device and a light-emitting apparatus. Thelight-emitting apparatus includes a means for emitting visible light anda means for emitting invisible light. The display device includes adisplay unit including a means for displaying an image and a means forobtaining positional information on a portion irradiated with thevisible light, and a means for receiving the invisible light. Thedisplay system has a function of performing processing in accordancewith the positional information when the invisible light is received.

Another embodiment of the present invention is a display systemincluding a display device and a light-emitting apparatus. The displaydevice includes a display unit and a light-receiving unit. The displayunit includes a plurality of display elements emitting visible light anda plurality of first light-receiving elements. The plurality of displayelements and the plurality of first light-receiving elements are eacharranged in a matrix. The light-receiving unit includes a secondlight-receiving element. The light-emitting apparatus includes a firstinput means, a second input means, a first light-emitting element, asecond light-emitting element, and an oscillator device. The firstlight-emitting element includes a laser light source exhibiting visiblelight, and a light emission state is controlled in accordance with aninput to the first input means. The second light-emitting elementincludes a light source exhibiting infrared light, and the oscillatordevice has a function of controlling a light emission state of thesecond light-emitting element in accordance with an input to the secondinput means. The first light-receiving element has a function ofreceiving the visible light emitted by the first light-emitting elementand converting the visible light into a first electric signal. Thesecond light-receiving element has a function of receiving the infraredlight emitted by the second light-emitting element and converting theinfrared light into a second electric signal.

Another embodiment of the present invention is a display deviceincluding a display unit and a light-receiving unit. The display unitincludes a plurality of display elements emitting visible light and aplurality of first light-receiving elements receiving visible light. Theplurality of display elements and the plurality of first light-receivingelements are each arranged in a matrix. The light-receiving unitincludes a second light-receiving element receiving infrared light.

In the above, the display element preferably includes a first pixelelectrode, a light-emitting layer, and a common electrode. The firstlight-receiving element preferably includes a second pixel electrode, anactive layer, and the common electrode. It is preferable that thelight-emitting layer and the active layer each include a differentorganic compound. The first pixel electrode and the second pixelelectrode are preferably provided over the same plane. The commonelectrode preferably includes a portion overlapping with the first pixelelectrode with the light-emitting layer therebetween, and a portionoverlapping with the second pixel electrode with the active layertherebetween.

In the above, the display element and the first light-receiving elementpreferably include a common layer. In that case, the common layerpreferably includes a portion located between the first pixel electrodeand the common electrode, and a portion located between the second pixelelectrode and the common electrode.

Another embodiment of the present invention is a light-emittingapparatus including a first input means, a second input means, a firstlight-emitting element, a second light-emitting element, and anoscillator device. The first light-emitting element includes a laserlight source exhibiting visible light, and a light emission state iscontrolled in accordance with an input to the first input means. Thesecond light-emitting element includes a light source exhibitinginfrared light. The oscillator device has a function of controlling alight emission state of the second light-emitting element in accordancewith an input to the second input means.

One embodiment of the present invention is a display system includingthe display device according to any of the above and the light-emittingapparatus. In that case, it is preferable that the first light-receivingelement have a function of receiving the visible light emitted by thefirst light-emitting element and converting the visible light into afirst electric signal, and the second light-receiving element have afunction of receiving the infrared light emitted by the secondlight-emitting element and converting the infrared light into a secondelectric signal.

Effect of the Invention

According to one embodiment of the present invention, a highlyconvenient display system can be provided. A display system enabling ascreen to be operated easily with a laser pointer can also be provided.A display system enabling a screen to be operated by a large number ofpeople can also be provided. A display device and a laser pointer device(a light-emitting apparatus) enabling the above display system can alsobe provided. A display device capable of obtaining positionalinformation on a portion pointed by a laser pointer can also beprovided. A device capable of operating a screen, which replaces aconventional laser pointer, can also be provided.

According to one embodiment of the present invention, a display devicewith a reduced manufacturing cost can also be provided. A high-qualitydisplay device, light-emitting apparatus, or display system can also beprovided. A highly reliable display device, light-emitting apparatus, ordisplay system can also be provided. A novel display device,light-emitting apparatus, or display system can also be provided.

Note that the description of these effects does not preclude theexistence of other effects. Note that one embodiment of the presentinvention does not need to have all these effects. Note that effectsother than these can be derived from the description of thespecification, the drawings, the claims, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagram illustrating a configuration example of a displaysystem.

FIG. 1B is a diagram illustrating a configuration example of a displaydevice.

FIG. 1C is a diagram illustrating a configuration example of alight-emitting apparatus.

FIG. 2A and FIG. 2B are diagrams each illustrating a configurationexample of a display device.

FIG. 3A to FIG. 3C are diagrams each illustrating an example ofoperation methods of a display system.

FIG. 4A and FIG. 4B are diagrams each illustrating an example ofoperation methods of a display system.

FIG. 5A to FIG. 5C are diagrams each illustrating an example ofoperation methods of a display system.

FIG. 6 is a diagram illustrating an example of operation methods of adisplay system.

FIG. 7 is a diagram illustrating an example of operation methods of adisplay system.

FIG. 8A to FIG. 8C are diagrams each showing a configuration example ofa display panel.

FIG. 9A and FIG. 9B are diagrams each showing a configuration example ofa display panel.

FIG. 10A to FIG. 10C are diagrams each showing a configuration exampleof a display panel.

FIG. 11 is a diagram illustrating a configuration example of a displaypanel.

FIG. 12 is a diagram illustrating a configuration example of a displaypanel.

FIG. 13A and FIG. 13B are diagrams each showing a configuration exampleof a display panel.

FIG. 14A and FIG. 14B are diagrams each showing a configuration exampleof a display panel.

FIG. 15 is a diagram showing a configuration example of a display panel.

FIG. 16A and FIG. 16B are each a circuit diagram of a pixel circuit.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments will be described with reference to thedrawings. Note that the embodiments can be implemented in many differentmodes, and it will be readily understood by those skilled in the artthat modes and details thereof can be changed in various ways withoutdeparting from the spirit and scope thereof. Thus, the present inventionshould not be construed as being limited to the following description ofthe embodiments.

Note that in configurations of the present invention described below,the same portions or portions having similar functions are denoted bythe same reference numerals in different drawings, and a descriptionthereof is not repeated. Furthermore, the same hatch pattern is used forthe portions having similar functions, and the portions are notespecially denoted by reference numerals in some cases.

Note that in each drawing described in this specification, the size, thelayer thickness, or the region of each component is exaggerated forclarity in some cases. Therefore, they are not limited to theillustrated scale.

Note that in this specification and the like, the ordinal numbers suchas “first” and “second” are used in order to avoid confusion amongcomponents and do not limit the number.

A transistor is a kind of semiconductor elements and can achieveamplification of current or voltage, switching operation for controllingconduction or non-conduction, or the like. An IGFET (Insulated GateField Effect Transistor) and a thin film transistor (TFT) are in thecategory of a transistor in this specification.

Note that the expressions indicating directions such as “over” and“under” are basically used to correspond to the directions of drawings.However, in some cases, the direction indicating “over” or “under” inthe specification does not correspond to the direction in the drawingsfor the purpose of description simplicity or the like. For example, whena stacked order (or formation order) of a stacked body or the like isdescribed, even in the case where a surface on which the stacked body isprovided (e.g., a formation surface, a support surface, an attachmentsurface, or a planarization surface) is positioned above the stackedbody in the drawings, the direction and the opposite direction arereferred to as “under” and “over”, respectively, in some cases.

In this specification and the like, the term “film” and the term “layer”can be interchanged with each other. For example, in some cases, theterm “conductive layer” and the term “insulating layer” can beinterchanged with the term “conductive film” and the term “insulatingfilm,” respectively.

In this specification and the like, a display panel that is oneembodiment of a display device has a function of displaying (outputting)an image or the like on (to) a display surface. Therefore, the displaypanel is one embodiment of an output device.

In this specification and the like, a substrate of a display panel towhich a connector such as an FPC (Flexible Printed Circuit) or a TCP(Tape Carrier Package) is attached, or a substrate on which an IC ismounted by a COG (Chip On Glass) method or the like is referred to as adisplay panel module, a display module, or simply a display panel or thelike in some cases.

Embodiment 1

In this embodiment, a display system of one embodiment of the presentinvention will be described.

Overview

The display system of one embodiment of the present invention includes adisplay device with a display unit (also referred to as a screen)displaying an image and a light-emitting apparatus emitting laser light.The light-emitting apparatus can be used as a laser pointer.

The light-emitting apparatus includes a light source (also referred toas a first light-emitting element or a first light-emitting device) thatemits visible laser light. The light-emitting apparatus further includesa light source (also referred to as a second light-emitting element or asecond light-emitting device) that emits nonvisible light (invisiblelight). Nonvisible light does not include visible light but may includeultraviolet light, infrared light, or an electromagnetic wave (electricwave) having a longer wavelength than infrared light. It is preferableto use, as nonvisible light, light having a longer wavelength thanvisible light, and it is particularly preferable to use infrared light.

Since the visible laser light emitted from the light-emitting apparatushas high directionality and a narrow irradiation range, a certain regionof the display unit can be pointed at by being irradiated with thevisible laser light. By contrast, light with lower directionality thanthat of the above visible laser light, i.e., light with a wideirradiation range can be used as the nonvisible light emitted from thelight-emitting apparatus.

A configuration may be employed in which the visible laser light can beemitted by operating a first switch included in the light-emittingapparatus. A configuration may be employed in which the nonvisible lightcan be emitted by operating a second switch included in thelight-emitting apparatus. In this manner, with a configuration in whichemission of the visible laser light and nonvisible light can beseparately operated, the light-emitting apparatus can be used as aconventional laser pointer when the second switch is not operated. Notethat not only physical switches but also sensing devices composed of avariety of sensors such as touch sensors (including touch pads), opticalsensors, acoustic sensors, acceleration sensors, and temperature sensorscan be used as the first switch and the second switch.

In the display unit of the display device, a plurality of pixels fordisplaying an image are arranged in a matrix. The pixels each include atleast one display element (also referred to as a display device). Inaddition, a plurality of first light-receiving elements (also referredto as first light-receiving devices) that receive the above visiblelaser light and convert it into electric signals (also referred to asfirst electric signals) are arranged in a matrix in the display unit. Aphotodiode can be used as the first light-receiving element, forexample. With the first light-receiving elements being arranged in amatrix in the display unit, the display device can obtain positionalinformation on a position irradiated with the visible laser light.

The display device includes a light-receiving unit in a portiondifferent from the display unit. The light-receiving unit includes asecond light-receiving element (also referred to as a secondlight-receiving device) that receives the above nonvisible light andconverts it into an electric signal (also referred to as a secondelectric signal).

In the display device, when the light-receiving unit receives nonvisiblelight, various types of processing can be executed on the basis of thepositional information on a portion which is irradiated with visiblelaser light. For example, processing for a character input function, adrawing function, or the like can be executed, as well as processingsuch as selection, execution, transfer, or the like of an objectdisplayed on the screen. Furthermore, processing for a gesture inputfunction can also be executed in accordance with the locus of positionsirradiated with visible laser light. Note that the types of processinggiven here are merely examples of the processing the display system canexecute, and various types of processing may be executed in accordancewith application software incorporated in the display system.

As described above, in the display system of one embodiment of thepresent invention, the light-emitting apparatus functioning as a laserpointer can also function as an input device such as a pointing device.This removes the necessity for an input device such as a mouse or atouch pad that has been conventionally needed, which leads to anincrease in convenience.

Furthermore, when information is included in the nonvisible lightemitted from the light-emitting apparatus, the display system canfurther be improved in convenience. For example, when nonvisible lightincludes identification information on a light-emitting apparatus, aplurality of users can operate the display system at the same time.Furthermore, nonvisible light can include information depending on theconfiguration or operation method of the second switch for controllingthe nonvisible light. For example, the time, timing, or the like ofemission of nonvisible light is used as information, whereby a functionequivalent to clicking, double-clicking, or long pressing of a mouse canbe performed. In addition, providing a plurality of the second switchesor using an input means such as touch-pad or dialing as the secondswitch enables analog input. In the case where information is includedin nonvisible light, the data is preferably overlapped with thenonvisible light by a modulation method such as pulse positionmodulation (PPM) or the like.

Here, the display element and the first light-receiving element providedin the display unit of the display device are preferably formed over thesame substrate. In that case, an organic electroluminescent element(organic EL element) containing an organic compound in a light-emittinglayer is preferably used as the display element and an organicphotodiode containing an organic compound in an active layer ispreferably used as the first light-receiving element. In addition, someof the manufacturing steps of the display element also serve as some ofthe manufacturing steps of the first light-receiving element, wherebymanufacturing cost can be reduced and the manufacturing yield can beincreased.

More specific examples of the display system, the display device, andthe light-emitting apparatus of one embodiment of the present inventionwill be described below with reference to drawings.

[Configuration Example of Display System]

FIG. 1A shows a schematic view of a display system 10. The displaysystem 10 includes a display device 11 and a light-emitting apparatus12.

The light-emitting apparatus 12 includes a switch 51 and a switch 52which are provided on a housing. The light-emitting apparatus 12 canemit visible light VL and infrared light IR from a tip of the housing.The visible light VL and the infrared light IR are emitted independentlyby the operation of the switch 51 and by the operation of the switch 52,respectively. Here, an example is shown in which a physical switch isused as each of the switch 51 and the switch 52.

As shown in FIG. 1A, the visible light VL is light with highdirectivity, and the infrared light IR is light with directivity lowerthan that of the visible light VL. In FIG. 1A, an irradiation region 59of the visible light VL is indicated by a solid line, and an irradiationregion 58 of the infrared light IR is indicated by a dashed line.

Laser light is preferably used as the visible light VL. For example, itis preferable to use red laser light (e.g., light with a peak wavelengthof greater than or equal to 620 nm and less than or equal to 700 nm) orgreen laser light (e.g., light with a peak wavelength of greater than orequal to 500 nm and less than or equal to 550 nm, typically around 532nm). Furthermore, the laser light is not limited to the above and can belight with a peak wavelength in a visible-light region (e.g., 350 nm to750 nm); for example, laser light with a variety of colors such as blue,yellow, orange, navy, or purple can also be used.

Light with a peak wavelength in a near-infrared region (greater than orequal to 750 nm and less than or equal to 2500 nm) is preferably used asthe infrared light IR. In addition, the directional characteristic(e.g., the viewing angle or full angle at half maximum) of the emissionintensity of the infrared light IR is preferably wider than that of thevisible light VL. For example, it is preferable to use light with a fullangle at half maximum of greater than or equal to 30°, preferablygreater than or equal to 40°, further preferably greater than or equalto 50° and less than or equal to 180°. Thus, in the state where adisplay unit 21 to be described later in the display device 11 isirradiated with the visible light VL, a light-receiving unit 30 providedoutside the display unit 21 can be irradiated with the infrared lightIR.

The display device 11 includes the display unit 21 and thelight-receiving unit 30.

The display unit 21 is a region of the display device 11 where an imageis displayed, and can also be referred to as a screen. The display unit21 has a function of receiving the visible light VL emitted from thelight-emitting apparatus 12 and obtaining positional information on theirradiation region 59 that is irradiated with the visible light VL.Here, it is preferable that the diameter and the area of the irradiationregion 59 on the display unit 21 be sufficiently smaller than (at least1/10 smaller than) the length in the short-side direction and the areaof the display unit 21.

A plurality of display elements 23 and a plurality of light-receivingelements 24 are respectively arranged in a matrix in the display unit21. FIG. 1A shows an enlarged view of part of the display unit 21. Anexample is shown here in which one pixel 22 includes a display element23R emitting red light, a display element 23B emitting blue light, adisplay element 23G emitting green light (hereinafter, the displayelements are collectively referred to as a display element 23 in somecases), and the light-receiving element 24 that receives visible lightto convert the visible light into an electric signal.

The arrangement interval of the display elements 23 and the arrangementinterval of the light-receiving elements 24 are the same here; however,the arrangement interval of the light-receiving elements 24 may belonger than the arrangement interval of the display elements 23. It isacceptable as long as the arrangement interval of the light-receivingelements 24 is shorter than the diameter of the irradiation region 59.The arrangement interval of the light-emitting elements 24 can beshorter than or equal to 10 mm, preferably shorter than or equal to 5mm, and more preferably less than or equal to 3 mm, for example. Theshorter the arrangement interval is, the more accurately the position ofthe irradiation region 59 can be detected. In the case where thearrangement interval of the display elements 23 and the arrangementinterval of the light-receiving elements 24 are different, thearrangement interval of the light-receiving elements 24 is preferablythe integral multiple of the arrangement interval of the displayelements 23 for easier design.

Laser light can be used as the visible light VL emitted from thelight-emitting apparatus 12; thus, the illuminance of the visible lightVL with which the irradiation region 59 is irradiated is extremelyhigher than that of external light. Therefore, the area of thelight-receiving element 24, more specifically, the effectivelight-receiving area of the light-receiving element 24 can besufficiently smaller than the effective light-emitting area of thedisplay element 23. Thus, the reduction in the aperture ratio (effectivedisplay area ratio) of the display unit 21 caused by the provision ofthe light-receiving element 24 can be extremely small. In addition, thesensitivity of the light-receiving element 24 is not required to behigh, so the range of choices for materials used for an active layer ofthe light-receiving element 24 can be widened, and the cost can belowered.

The light-receiving unit 30 has a function of receiving the infraredlight IR emitted from the light-emitting apparatus 12 and converting theinfrared light IR into an electric signal. The light-receiving unit 30may be provided with a plurality of light-receiving elements thatreceive the infrared light IR or one light-receiving element. An examplein which the light-receiving unit 30 is provided outside the displayunit 21 is shown here; however, the light-receiving unit 30 may bepositioned inside the outline of the display unit 21, or a configurationmay be employed in which an aperture that transmits the infrared lightIR is provided in the display unit 21 and the light-receiving unit 30 isprovided to overlap with the aperture. Furthermore, in the case wherethe display unit 21 transmits the infrared light IR, the light-receivingunit 30 may be provided on the backside of the display unit 21. In amanner similar to the light-receiving element 24 included in the displayunit 21, a light-receiving element that constitutes the light-receivingunit 30 may be formed in the display unit 21. Alternatively, an elementthat can receive both the visible light VL and the infrared light IR maybe used as the light-receiving element 24 and the display unit 21 mayalso serve as the light-receiving unit 30.

[Configuration Example of Display Device]

FIG. 1B is a block diagram showing an example of the display device 11.The display device 11 includes a display panel 20, the light-receivingunit 30, a control unit 41, a driver unit 42, a driver unit 43, and thelike.

The display panel 20 includes the display unit 21, a driver circuit 25,a driver circuit 26, and the like. The display unit 21 includes aplurality of pixels 22 arranged in a matrix. Here, an example in whichthe pixel 22 includes the display element 23 and the light-receivingelement 24 is shown.

The driver circuit 25 is a circuit for controlling driving of thedisplay element 23. A circuit having a function of a source driver and agate driver, for example, can be used as the driver circuit 25. Thedriver circuit 25 drives the pixels 22 in accordance with signalssupplied from the driver unit 42 so that an image can be displayed onthe display unit 21.

The driver circuit 26 has a function of controlling driving of thelight-receiving element 24 and a function of reading an electric signaloutput from the light-receiving element 24 and outputting the electricsignal to the driver unit 42. A circuit having a function of a readoutcircuit including a plurality of sense amplifiers, AD converters, or thelike and a function of a selection circuit selecting the light-receivingelement 24, for example, can be used as the driver circuit 26.

The light-receiving unit 30 includes at least one light-receivingelement 31. The light-receiving unit 30 has a function of driving thelight-receiving element 31 and a function of outputting, to the driverunit 43, an electric signal output from the light-receiving element 31.

The driver unit 42 has a function of generating a signal to be output tothe display panel 20, in accordance with a signal input from the controlunit 41, and outputting the signal, and a function of converting asignal input from the display panel 20 into a signal to be output to thecontrol unit 41 and outputting the signal. The driver unit 42 includes,for example, a timing controller, a DA converter, an AD converter, anamplifier, a buffer, and the like.

The driver unit 43 has a function of generating a signal to be output tothe light-receiving unit 30, in accordance with a signal input from thecontrol unit 41, and outputting the signal, and a function of convertinga signal input from the light-receiving unit 30 into a signal to beoutput to the control unit 41 and outputting the signal. The driver unit43 includes, for example, a timing controller, a DA converter, an ADconverter, an amplifier, a buffer, and the like.

In FIG. 1B, a signal S1 and a signal S2, which are input to the controlunit 41, and a signal S3, which is output by the control unit 41, areindicated by arrows. The signal S1 contains data on the positionalinformation on the irradiation region 59 of the visible light VLreceived by the display unit 21, and the like. The signal S2 containsdata related to the infrared light IR received by the light-receivingunit 30, and the like. The control unit 41 can perform various types ofprocessing in accordance with the signal S2 and the signal S3. Inaddition, in accordance with the processing, the control unit 41 cangenerate the signal S3 containing data on an image to be displayed onthe display unit 21 and output the signal S3 to the driver unit 42.

The control unit 41 can have a configuration including a processor suchas a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit).The control unit 41 interprets and executes instructions from variousprograms with use of a processor to process various kinds of data andcontrol programs. Programs that might be executed by the processor maybe stored in a memory region of the processor or may be stored in adifferent memory module.

FIG. 2A and FIG. 2B each show a different configuration example of thedisplay device 11.

The configuration shown in FIG. 2A illustrates an example in which thedisplay device 11 is divided into a display module 15 and a controldevice 16. This is an example of a case where a computer is used as thecontrol device 16, for example. In that case, the display module 15 canfunction as a monitor device, a television device, or the like that canbe connected to a computer with a cable, wireless communication, or thelike.

The display module 15 includes the display panel 20, the light-receivingunit 30, a driver unit 42 a, and a driver unit 43 a. The control device16 includes the control unit 41, a driver unit 42 b, and a driver unit43 b.

The driver unit 42 a and the driver unit 42 b each have a function of aninterface for communication between the display module 15 and thecontrol device 16; other than that, the driver unit 42 a and the driverunit 42 b make up a pair having a function similar to that of theabove-described driver unit 42. The driver unit 42 a and the driver unit42 b are capable of encoding, combining, or the like of electric signalsin accordance with the communication standards, and capable oftransmitting signals between the two, for example. Similarly, the driverunit 43 a and the driver unit 43 b each have a function of an interface.

Note that the driver unit 42 a and the driver unit 43 a, or the driverunit 42 b and the driver unit 43 b are described as separate componentsfrom each other here to make the description easier; however, the driverunit 42 a and the driver unit 43 a or the driver unit 42 b and thedriver unit 43 b can each be fabricated as one component.

The configuration shown in FIG. 2B is an example in which the displaydevice 11 is divided into a display module 15 a, a light-receivingmodule 15 b, and the control device 16. A configuration that the displaymodule 15 a and the light-receiving module 15 b each have is similar tothe configuration of the display module 15 shown in FIG. 2A.

[Configuration Example of Light-Emitting Apparatus]

FIG. 1C is a block diagram showing an example of the light-emittingapparatus 12. The light-emitting apparatus 12 includes the switch 51,the switch 52, a light-emitting element 53, a light-emitting element 54,a driver unit 55, a signal generation unit 56, a driver unit 57, and thelike.

The light-emitting element 53 functions as a light source emitting thevisible light VL, which is visible laser light. A semiconductor laserelement, in particular, is preferably used as the light-emitting element53, in which case the light-emitting apparatus 12 can be lightweight.

Examples of the semiconductor laser element that can be used as thelight-emitting element 53 include an edge emitting laser (EEL) and asurface emitting laser (SEL). Examples of the surface emitting laserinclude a vertical cavity surface emitting laser (VCSEL) and a verticalexternal cavity surface emitting laser (VECSEL).

As the light-emitting element 53, a semiconductor laser element thatsatisfies Class 1, Class 1M, Class 2, or Class 2M in accordance withclassification by Japanese Industrial Standards (JIS C 6802) or IECstandards (IEC 60825-1) is preferably used. For example, a semiconductorlaser element with a laser output value of 1 mW or less, orapproximately 0.2 mW is preferably used.

The driver unit 55 has a function of controlling light emission ornon-light emission of the light-emitting element 53, in accordance withthe operation of the switch 51. The simplest configuration of the driverunit 55 can be a configuration in which a physical switch is used as theswitch 51, and the switch 51, a power source, and the light-emittingelement 53 are connected in series. An appropriate circuit or the likecan be used for the driver unit 55, depending on the configurations ofthe switch 51 and the light-emitting element 53, the light-emittingmethod of the light-emitting element 53, or the like.

The light-emitting element 54 functions as a light source emitting theinfrared light IR. A light emitting diode (LED) can be suitably used asthe light-emitting element 54.

The light-emitting diode can be a bullet type, a surface mount device(SMD) type, a chip on board (COB) type, or the like. The use of thebullet type LED can reduce the cost. The use of the surface mount typeLED or the chip on board type LED can improve the luminance anddurability.

The signal generation unit 56 is a circuit that generates a signal forsuperimposing data on the infrared light IR emitted from thelight-emitting element 54. The signal generation unit 56 can generate asignal in accordance with a modulation method such as a pulse positionmodulation method, in response to the operation of the switch 52, andoutput the signal to the driver unit 57.

The driver unit 57 has a function of controlling light emission andnon-light emission of the light-emitting element 54 in accordance withthe signal generated in the signal generation unit 56.

The signal generation unit 56 and the driver unit 57 can be collectivelyreferred to as an oscillator device. The oscillator device has afunction of controlling a light emission state of the light-emittingelement 54 in accordance with an input to the switch 52.

Here, data generated in the signal generation unit 56 preferablycontains identification data of devices. This enables the display system10 to be operated by a plurality of users at a time.

In FIG. 1C, a configuration of the light-emitting apparatus 12 in whicha system with the switch 51 to the light-emitting element 53 and asystem with the switch 52 to the light-emitting element 54 areindependent from each other is shown. With this configuration, thelight-emitting apparatus 12 can be fabricated very easily, which canreduce the manufacturing cost. Note that the configuration of thelight-emitting apparatus 12 is not limited to this; it is acceptable aslong as the configuration includes at least the light-emitting element53, the light-emitting element 54, and an operation means such as aswitch.

[Processing Example of Display System]

The display system of one embodiment of the present invention canperform various types of processing depending on the positionalinformation on an irradiation region of visible light emitted from alight-emitting apparatus operated by a user and information contained ininfrared light. Most of the processing performed by the display systeminvolves changes of images displayed on a display unit. In that case,the display system has a function of performing the processing forgenerating a new image and updating a screen.

Furthermore, the display system of one embodiment of the presentinvention enables the screen to be remotely operated by users fromlocations physically apart from the screen, with a light-emittingapparatus serving as a laser pointer as well. An example of operationsthat can be performed by a user through the processing of the displaysystem will be described hereinafter with reference to drawings.

Note that the following processing method, operation method, performancemethod, or display method that may be employed by the display system 10can be referred to as a program, for example. In addition, a program inwhich the processing method, operation method, performance method, ordisplay method to be described below is written can be stored in anon-temporary storage medium and can be read and executed by anarithmetic device or the like included in the control unit 41 of thedisplay system 10. That is, a program that makes hardware to execute theprocessing method, operation method, performance method, or displaymethod described below or a non-temporary memory medium where theprogram is stored is of one embodiment of the present invention.

Operation Method Example 1

FIG. 3A schematically shows the display device 11 and a user 60operating the screen using the light-emitting apparatus 12.

The user 60 can perform emission of the visible light VL by operatingthe switch 51 of the light-emitting apparatus 12. In addition, byoperating the switch 52 of the light-emitting apparatus 12, the user 60can make the display system 10 execute various types of processing withthe infrared light IR (not shown).

The display device 11 is provided with the display unit 21, and thelight-receiving unit 30 in a region that does not overlap with thedisplay unit 21. An object 61 is displayed on the display unit 21.

FIG. 3A shows a state where the user 60 is moving the object 61displayed on the display unit 21 using the light-emitting apparatus 12.

When the visible light VL is emitted such that the irradiation region 59is positioned in part of the object 61 (the upper portion of the object61 in FIG. 3A) and the irradiation region 59 is moved, the object 61 canbe moved along the locus of the irradiation region 59.

This operation corresponds to the drag operation in the case of using amouse. The user 60 can drag the object 61 by moving the irradiationregion 59 with the switch 52 being pressed, and can determine theposition of the object 61 by releasing the switch 52, for example.

Note that the function of the drag operation is an example; the user 60can intuitively perform, with the use of the light-emitting apparatus12, operations equivalent to click, double click, long-press operation,and other operations that are conventionally performed with the use of amouse. In addition, when two or more switches 52 are provided, thefunctionality of the light-emitting apparatus 12 can be improved, like amouse with two or more buttons.

FIG. 3B shows a state where the display system 10 is executing a drawingfunction. The user 60 can draw a figure (an object 62) or the like alongthe locus of the irradiation region 59 on the display unit 21 byoperating the light-emitting apparatus 12.

Although not shown here, an icon image for changing the thickness, kind,color, or the like of a drawing line may be displayed on the displayunit 21, for example. In addition, a function of drawing various figuressuch as a rectangle, a polygon, a circle, an ellipse, and a half circleas well as a line may be given.

FIG. 3C shows a state where the display system 10 is executing atext-inputting function. The user 60 can draw a text (an object 63)freehand, by operating the light-emitting apparatus 12. The displaysystem 10 can identify the text that best resembles the shape of theobject 63, and display the text as text information.

In FIG. 3C, a state where the user 60 draws a numeral “5” and thenumeral “5” is displayed as text information.

Operation Method Example 2

The display system 10 may have a function of recognizing the locus ofthe irradiation region 59 and using this as an input operation (alsoreferred to as a gesture input).

FIG. 4A shows a state where an operation of displaying an enlarged imageof information included in an object 66 a is performed by a gestureinput. When the user 60 operates the light-emitting apparatus 12 suchthat a locus 65 of the irradiation region 59 draws a rough circle, theobject 66 a is changed into an object 66 b with information includingthe range enclosed by the locus 65 being enlarged.

In contrast to the above, FIG. 4B shows a state where an operation ofdisplaying information included in an object 67 a being reduced in size,is performed by a gesture input. When the user 60 operates thelight-emitting apparatus 12 such that the locus 65 of the irradiationregion 59 draws a rough triangle, the object 67 a is changed into anobject 67 b with information including the range enclosed by the locus65, displayed with a reduced size but with a wider range.

As described above, when the display system 10 has a configuration thatallows gesture inputs using the light-emitting apparatus 12, the user 60can operate the screen more intuitively, which makes the display system10 more user-friendly.

Operation Method Example 3

A menu for switching the operation modes by the light-emitting apparatus12 can be displayed on the display unit 21 of the display system 10,which allows the user 60 to select functions from the menu.

FIG. 5A shows a state where an object 61 is displayed on the displayunit 21. In this state, when the irradiation region 59 is moved close tothe periphery of the display unit 21, a menu image (an object 68)including a variety of icons (here, icons 69 a to 69 d) appears as shownin FIG. 5B or FIG. 5C. With a function of hiding the menu image whenunnecessary and displaying the menu image when necessary as describedabove, the display region can be effectively utilized, which ispreferable.

FIG. 5B shows an example in which the menu image appears from the sideof the display unit 21, and FIG. 5C shows an example in which the menuimage appears from the top of the display unit 21. The position wherethe menu image is displayed may be fixed; the operability can be furtherimproved in the case where the menu image is configured to appear whenthe irradiation region 59 comes close to anywhere in the periphery ofthe display unit 21. It is preferable that the position where the menuimage appears can be set by a user. Alternatively, display of the menuimage may be performed by a gesture input.

By selecting the icon 69 a shown in FIG. 5C, operation by thelight-emitting apparatus 12 can be switched into an object operationmode, for example. By selecting the icon 69 b, operation by thelight-emitting apparatus 12 can be switched into a drawing mode. Byselecting the icon 69 c, operation by the light-emitting apparatus 12can be switched into a background-image operation mode. By selecting theicon 69 d, operation by the light-emitting apparatus 12 can be switchedinto a gesture input mode.

As described above, providing the display system 10 with a function ofvariously switching the modes eliminates the need for the light-emittingapparatus 12 itself to have a number of functions, and enables operationby the light-emitting apparatus 12 with a simple configuration. Thus,the manufacturing cost of the light-emitting apparatus 12 can bereduced.

Operation Method Example 4

The display system of one embodiment of the present invention can beoperated by a plurality of users using light-emitting apparatuses.

FIG. 6 shows a meeting being held with the use of the display system 10.The material used for the meeting is displayed on the display unit 21 ofthe display device 11.

A user 60 a and a user 60 b among people attending the meeting each havea light-emitting apparatus 12 a or a light-emitting apparatus 12 b.

The user 60 a is performing operation in the drawing mode. FIG. 6 showsan irradiation region 59 a of visible light VLa emitted from thelight-emitting apparatus 12 a, and an image of handwritten texts (anobject 64) drawn along the locus of the irradiation region 59 a.

The user 60 b is using the light-emitting apparatus 12 b as a laserpointer. The user 60 b is pointing a portion of the display unit 21 withan irradiation region 59 b of visible light VLb.

A piece of different identification information is superimposed oninfrared light IR (not shown) emitted from each of the light-emittingapparatus 12 a and the light-emitting apparatus 12 b. This enables theuser 60 a and the user 60 b to operate the screen independently of eachother.

The visible light VLa emitted from the light-emitting apparatus 12 a andthe visible light VLb emitted from the light-emitting apparatus 12 bpreferably have different wavelengths. In that case, from whichlight-emitting apparatus the irradiation region 59 a or the irradiationregion 59 b is derived can be identified by the wavelength, which allowssimultaneous operation by the user 60 a and the user 60 b.

It is also possible to distinguish the irradiation region 59 a from theirradiation region 59 b by superimposing, on the infrared light IRemitted from each of the light-emitting apparatus 12 a and thelight-emitting apparatus 12 b, information on the direction in which thevisible light VLa or the visible light VLb is emitted. For example, aconfiguration may be employed in which the light-emitting apparatus 12 aand the light-emitting apparatus 12 b each include a sensor that detectsthe inclination or direction of the apparatus itself (an accelerationsensor, for example), a sensor that detects the direction in which thevisible light VLa or the visible light VLb is emitted (a camera, forexample), or the like and information obtained by the sensor istransmitted by being superimposed on the infrared light IR.

Alternatively, the display device 11 may include a means for detectingthe directions or positions of the light-emitting apparatus 12 a and thelight-emitting apparatus 12 b (a camera, for example) and have afunction of determining the directions in which the visible light VLaand the visible light VLb are emitted.

FIG. 7 shows a plurality of users of the display system 10 enjoying agame. A plurality of objects 61 shaped like moving flight vehicles orunknown creatures are displayed as targets on the display unit 21.

The user 60 a and the user 60 b operate the switch 52 for emitting theinfrared light IR (not shown) in a state where the irradiation region 59a or the irradiation region 59 b is pointed at the object 61 to destroythe object 61, whereby the user 60 a and the user 60 b can score apoint. Points scored by each of the users (indicated as “Score”) and theremaining time (indicated as “TIME”) are displayed on the upper portionof the display unit 21.

The above is the description of examples of operation that can beperformed by a user with the processing of the display system.

According to one embodiment of the present invention, the display systemthat can execute processing based on information on a positionirradiated with visible laser light in a display unit and informationcontained in nonvisible light received by the light-receiving unit andthat can reflect the processing result in display can be provided. Oneembodiment of the present invention is the display device that canachieve the display system, and another embodiment of the presentinvention is a light-emitting apparatus that can achieve the displaysystem. The display device and the light-emitting apparatus that canconstitute the display system can be manufactured and sold independentlyof each other.

According to one embodiment of the present invention, a display systemwith a high convenience, a display system capable of easy operation of ascreen using a laser pointer, a display system capable of operation of ascreen by a plurality of users, or the like can be achieved.

At least part of this embodiment can be implemented in combination withthe other embodiments described in this specification as appropriate.

Embodiment 2

In this embodiment, a display panel that can be used for the displaysystem described in Embodiment 1 will be described with reference todrawings.

A display panel of one embodiment of the present invention includes adisplay element exhibiting visible light and a light-receiving element(a light-receiving device) that receives infrared light. The displayelement is preferably a light-emitting element (also referred to as alight-emitting device). The light-receiving element is preferably aphotoelectric conversion element.

Here, in the case where a light-emitting element is used as the displayelement, an EL element such as an OLED (Organic Light Emitting Diode) ora QLED (Quantum-dot Light Emitting Diode) is preferably used. As alight-emitting substance of the EL element, a substance emittingfluorescence (a fluorescent material), a substance emittingphosphorescence (a phosphorescent material), a substance exhibitingthermally activated delayed fluorescence (a TADF material), an inorganiccompound (e.g., a quantum dot material), or the like can be used.Alternatively, as a light emitting element, to increase the flexibilityof an LED such as a micro-LED (Light Emitting Diode)

As the light-receiving element, a pn-type or pin-type photodiode can beused, for example. The light-receiving element functions as aphotoelectric conversion element that detects light incident on thelight-receiving element and generates charge. The amount of generatedcharge in the photoelectric conversion element is determined dependingon the amount of incident light. It is particularly preferable to use anorganic photodiode including a layer containing an organic compound asthe light-receiving element. An organic photodiode, which is easily madethin, lightweight, and large in area and has a high degree of freedomfor shape and design, can be used in a variety of display devices.

The light-emitting element can have a stacked-layer structure includinga light-emitting layer between a pair of electrodes, for example. Thelight-receiving element can have a stacked-layer structure including anactive layer between the pair of electrodes. A semiconductor materialcan be used for the active layer of the light-receiving element. Forexample, an inorganic semiconductor material such as silicon can beused.

It is particularly preferable to use an organic compound for the activelayer of the light-receiving element. In that case, the light-emittingelement and one electrode (also referred to as a pixel electrode) of thelight-receiving element are preferably provided on the same plane. Inaddition, the light-emitting element and the other electrode of thelight-receiving element are further preferably formed using onecontinuous conductive layer (also referred to as a common electrode).Furthermore, it is still further preferable that the light-emittingelement and the light-receiving element include a common layer. Thus,the manufacturing process of the light-emitting element and thelight-receiving element can be simplified, so that the manufacturingcost can be reduced and the manufacturing yield can be increased.

Examples that are more specific will be described below with referenceto drawings.

Configuration Example 1 of Display Panel Configuration Example 1-1

FIG. 8A is a schematic cross-sectional view of a display panel 100A.

The display panel 100A includes a light-receiving element 110 and alight-emitting element 190. The light-receiving element 110 includes apixel electrode 111, a common layer 112, an active layer 113, a commonlayer 114, and a common electrode 115. The light-emitting element 190includes a pixel electrode 191, the common layer 112, a light-emittinglayer 193, the common layer 114, and the common electrode 115.

The pixel electrode 111, the pixel electrode 191, the common layer 112,the active layer 113, the light-emitting layer 193, the common layer114, and the common electrode 115 may each have a single-layer structureor a stacked-layer structure.

The pixel electrode 111 and the pixel electrode 191 are positioned overan insulating layer 214. The pixel electrode 111 and the pixel electrode191 can be formed using the same material in the same step.

The common layer 112 is positioned over the pixel electrode 111 and thepixel electrode 191. The common layer 112 is shared by thelight-receiving element 110 and the light-emitting element 190.

The active layer 113 overlaps with the pixel electrode 111 with thecommon layer 112 therebetween. The light-emitting layer 193 overlapswith the pixel electrode 191 with the common layer 112 therebetween. Theactive layer 113 includes a first organic compound, and thelight-emitting layer 193 includes a second organic compound that isdifferent from the first organic compound.

The common layer 114 is positioned over the common layer 112, the activelayer 113, and the light-emitting layer 193. The common layer 114 isshared by the light-receiving element 110 and the light-emitting element190.

The common electrode 115 includes a portion overlapping with the pixelelectrode 111 with the common layer 112, the active layer 113, and thecommon layer 114 therebetween. The common electrode 115 further includesa portion overlapping with the pixel electrode 191 with the common layer112, the light-emitting layer 193, and the common layer 114therebetween. The common electrode 115 is shared by the light-receivingelement 110 and the light-emitting element 190.

In the display panel of this embodiment, an organic compound is used forthe active layer 113 of the light-receiving element 110. In thelight-receiving element 110, the layers other than the active layer 113can be common to the layers in the light-emitting element 190 (the ELelement). Therefore, the light-receiving element 110 can be formedconcurrently with the formation of the light-emitting element 190 onlyby adding a step of depositing the active layer 113 in the manufacturingprocess of the light-emitting element 190. The light-emitting element190 and the light-receiving element 110 can be formed over onesubstrate. Accordingly, the light-receiving element 110 can beincorporated in the display panel without a significant increase in thenumber of manufacturing steps.

The display panel 100A shows an example in which the light-receivingelement 110 and the light-emitting element 190 have a common structureexcept that the active layer 113 of the light-receiving element 110 andthe light-emitting layer 193 of the light-emitting element 190 areseparately formed. Note that the structures of the light-receivingelement 110 and the light-emitting element 190 are not limited thereto.The light-receiving element 110 and the light-emitting element 190 mayinclude a separately formed layer other than the active layer 113 andthe light-emitting layer 193 (see display panels 100D, 100E, and 100F tobe described later). The light-receiving element 110 and thelight-emitting element 190 preferably include at least one layer used incommon (common layer). Thus, the light-receiving element 110 can beincorporated in the display panel without a significant increase in thenumber of manufacturing steps.

The display panel 100A includes the light-receiving element 110, thelight-emitting element 190, a transistor 131, a transistor 132, and thelike between a pair of substrates (a substrate 151 and a substrate 152).

In the light-receiving element 110, the common layer 112, the activelayer 113, and the common layer 114 that are positioned between thepixel electrode 111 and the common electrode 115 can each be referred toas an organic layer (a layer containing an organic compound). The pixelelectrode 111 preferably has a function of reflecting visible light. Anend portion of the pixel electrode 111 is covered with a partition 216.The common electrode 115 has a function of transmitting visible light.

The light-receiving element 110 has a function of detecting light.Specifically, the light-receiving element 110 is a photoelectricconversion element that receives light 122 entering from the outsidethrough the substrate 152 and converts the light 122 into an electricalsignal.

A light-blocking layer BM is provided on a surface of the substrate 152on the substrate 151 side. The light-blocking layer BM has an opening ata position overlapping with the light-receiving element 110 and anopening at a position overlapping with the light-emitting element 190.Providing the light-blocking layer BM can control the range where thelight-receiving element 110 detects light.

For the light-blocking layer BM, a material that blocks light emittedfrom the light-emitting element can be used. The light-blocking layer BMpreferably absorbs visible light. As the light-blocking layer BM, ablack matrix can be formed using a metal material or a resin materialcontaining pigment (e.g., carbon black) or dye, for example. Thelight-blocking layer BM may have a stacked-layer structure of a redcolor filter, a green color filter, and a blue color filter.

Here, part of light emitted from the light-emitting element 190 isreflected in the display panel 100A and is incident on thelight-receiving element 110 in some cases. The light-blocking layer BMcan reduce the influence of such stray light. For example, in the casewhere the light-blocking layer BM is not provided, light 123 a emittedfrom the light-emitting element 190 is reflected by the substrate 152and reflected light 123 b is incident on the light-receiving element 110in some cases. Providing the light-blocking layer BM can inhibit entryof the reflected light 123 b into the light-receiving element 110.Consequently, noise can be reduced, and the sensitivity of a sensorusing the light-receiving element 110 can be increased.

In the light-emitting element 190, the common layer 112, thelight-emitting layer 193, and the common layer 114 that are positionedbetween the pixel electrode 191 and the common electrode 115 can each bereferred to as an EL layer. The pixel electrode 191 preferably has afunction of reflecting visible light. An end portion of the pixelelectrode 191 is covered with the partition 216. The pixel electrode 111and the pixel electrode 191 are electrically insulated from each otherby the partition 216. The common electrode 115 has a function oftransmitting visible light.

The light-emitting element 190 has a function of emitting visible light.Specifically, the light-emitting element 190 is an electroluminescentlight-emitting element that emits light 121 toward the substrate 152when voltage is applied between the pixel electrode 191 and the commonelectrode 115.

It is preferable that the light-emitting layer 193 be formed not tooverlap with a light-receiving region of the light-receiving element110. Accordingly, it is possible to inhibit the light-emitting layer 193from absorbing the light 122, so that the amount of light with which thelight-receiving element 110 is irradiated can be increased.

The pixel electrode 111 is electrically connected to a source or a drainof the transistor 131 through an opening provided in the insulatinglayer 214. The end portion of the pixel electrode 111 is covered withthe partition 216.

The pixel electrode 191 is electrically connected to a source or a drainof the transistor 132 through an opening provided in the insulatinglayer 214. The end portion of the pixel electrode 191 is covered withthe partition 216. The transistor 132 has a function of controllingdriving of the light-emitting element 190.

The transistor 131 and the transistor 132 are on and in contact with thesame layer (the substrate 151 in FIG. 8A).

At least part of a circuit electrically connected to the light-receivingelement 110 is preferably formed using the same material in the samesteps as a circuit electrically connected to the light-emitting element190. Thus, the thickness of the display panel can be reduced and themanufacturing process can be simplified compared to the case where thetwo circuits are separately formed.

The light-receiving element 110 and the light-emitting element 190 arepreferably covered with a protective layer 195. In FIG. 8A, theprotective layer 195 is provided on and in contact with the commonelectrode 115. Providing the protective layer 195 can inhibit entry ofimpurities such as water into the light-receiving element 110 and thelight-emitting element 190, so that the reliability of thelight-receiving element 110 and the light-emitting element 190 can beincreased. The protective layer 195 and the substrate 152 are attachedto each other with an adhesive layer 142.

Note that as shown in FIG. 9A, the protective layer is not necessarilyprovided over the light-receiving element 110 and the light-emittingelement 190. In FIG. 9A, the common electrode 115 and the substrate 152are attached to each other with the adhesive layer 142.

As shown in FIG. 9B, the light-blocking layer BM is not necessarilyprovided. This structure can increase the light-receiving area of thelight-receiving element 110, so that the sensitivity of the sensor canbe further increased.

Configuration Example 1-2

FIG. 8B is a cross-sectional view of a display panel 100B. Note that inthe following description of display panels, the description ofcomponents similar to those of the above display panel might be omitted.

The display panel 100B shown in FIG. 8B includes a lens 149 in additionto the components of the display panel 100A.

The lens 149 is provided at a position overlapping with thelight-receiving element 110. In the display panel 100B, the lens 149 isprovided in contact with the substrate 152. The lens 149 included in thedisplay panel 100B is a convex lens having a convex surface on thesubstrate 151 side. Note that convex lens having a convex surface on thesubstrate 152 side may be provided in a region overlapping with thelight-receiving element 110.

In the case where the light-blocking layer BM and the lens 149 areformed on the same plane of the substrate 152, their formation order isnot limited. FIG. 8B shows an example in which the lens 149 is formedfirst; alternatively, the light-blocking layer BM may be formed first.In FIG. 8B, an end portion of the lens 149 is covered with thelight-blocking layer BM.

In the display panel 100B, the light 122 is incident on thelight-receiving element 110 through the lens 149. With the lens 149, theamount of the light 122 incident on the light-receiving element 110 canbe increased compared to the case where the lens 149 is not provided.This can increase the sensitivity of the light-receiving element 110.

As a method for forming the lens used in the display panel of thisembodiment, a lens such as a microlens may be formed directly over thesubstrate or the light-receiving element, or a lens array formedseparately, such as a microlens array, may be attached to the substrate.

Configuration Example 1-3

FIG. 8C is a schematic cross-sectional view of a display panel 100C. Thedisplay panel 100C differs from the display panel 100A in that thesubstrate 151, the substrate 152, and the partition 216 are not includedand a substrate 153, a substrate 154, an adhesive layer 155, aninsulating layer 212, and a partition 217 are included.

The substrate 153 and the insulating layer 212 are attached to eachother with the adhesive layer 155. The substrate 154 and the protectivelayer 195 are attached to each other with the adhesive layer 142.

The display panel 100C is formed in such a manner that the insulatinglayer 212, the transistor 131, the transistor 132, the light-receivingelement 110, the light-emitting element 190, and the like that areformed over a formation substrate are transferred onto the substrate153. The substrate 153 and the substrate 154 are preferably flexible.Accordingly, the display panel 100C can be highly flexible. For example,a resin is preferably used for each of the substrate 153 and thesubstrate 154.

For each of the substrate 153 and the substrate 154, any of thefollowing can be used, for example: polyester resins such aspolyethylene terephthalate (PET) and polyethylene naphthalate (PEN), apolyacrylonitrile resin, an acrylic resin, a polyimide resin, apolymethyl methacrylate resin, a polycarbonate (PC) resin, apolyethersulfone (PES) resin, polyamide resins (e.g., nylon and aramid),a polysiloxane resin, a cycloolefin resin, a polystyrene resin, apolyamide-imide resin, a polyurethane resin, a polyvinyl chloride resin,a polyvinylidene chloride resin, a polypropylene resin, apolytetrafluoroethylene (PTFE) resin, an ABS resin, and cellulosenanofiber. Glass that is thin enough to have flexibility may be used forone or both of the substrate 153 and the substrate 154.

For the substrate included in the display panel of this embodiment, afilm having high optical isotropy may be used. Examples of the filmhaving high optical isotropy include a triacetyl cellulose (TAC, alsoreferred to as cellulose triacetate) film, a cycloolefin polymer (COP)film, a cycloolefin copolymer (COC) film, and an acrylic film.

The partition 217 preferably absorbs light emitted from thelight-emitting element. As the partition 217, a black matrix can beformed using a resin material containing pigment or dye, for example.Moreover, the partition 217 can be formed of a colored insulating layerby using a brown resist material.

Light 123 c emitted from the light-emitting element 190 might bereflected by the substrate 152 and the partition 217 and reflected light123 d might be incident on the light-receiving element 110. In othercases, the light 123 c passes through the partition 217 and is reflectedby a transistor, a wiring, or the like, and thus reflected light isincident on the light-receiving element 110. When the partition 217absorbs the light 123 c, the reflected light 123 d can be inhibited frombeing incident on the light-receiving element 110. Consequently, noisecan be reduced, and the sensitivity of the sensor using thelight-receiving element 110 can be increased.

The partition 217 preferably absorbs at least a wavelength of light thatis detected by the light-receiving element 110. For example, in the casewhere the light-receiving element 110 detects red light emitted from thelight-emitting element 190, the partition 217 preferably absorbs atleast red light. For example, when the partition 217 includes a bluecolor filter, the partition 217 can absorb the red light 123 c and thusthe reflected light 123 d can be inhibited from being incident on thelight-receiving element 110.

Configuration Example 1-4

Although the light-emitting element and the light-receiving elementinclude two common layers in the above example, one embodiment of thepresent invention is not limited thereto. Examples in which commonlayers have different structures are described below.

FIG. 10A is a schematic cross-sectional view of the display panel 100D.The display panel 100D differs from the display panel 100A in that thecommon layer 114 is not included and a buffer layer 184 and a bufferlayer 194 are included. The buffer layer 184 and the buffer layer 194may each have a single-layer structure or a stacked-layer structure.

In the display panel 100D, the light-receiving element 110 includes thepixel electrode 111, the common layer 112, the active layer 113, thebuffer layer 184, and the common electrode 115. In the display panel100D, the light-emitting element 190 includes the pixel electrode 191,the common layer 112, the light-emitting layer 193, the buffer layer194, and the common electrode 115.

In the display panel 100D, an example is shown in which the buffer layer184 between the common electrode 115 and the active layer 113 and thebuffer layer 194 between the common electrode 115 and the light-emittinglayer 193 are formed separately. As the buffer layer 184 and the bufferlayer 194, one or both of an electron-injection layer and anelectron-transport layer can be formed, for example.

FIG. 10B is a schematic cross-sectional view of the display panel 100E.The display panel 100E differs from the display panel 100A in that thecommon layer 112 is not included and a buffer layer 182 and a bufferlayer 192 are included. The buffer layer 182 and the buffer layer 192may each have a single-layer structure or a stacked-layer structure.

In the display panel 100E, the light-receiving element 110 includes thepixel electrode 111, the buffer layer 182, the active layer 113, thecommon layer 114, and the common electrode 115. In the display panel100E, the light-emitting element 190 includes the pixel electrode 191,the buffer layer 192, the light-emitting layer 193, the common layer114, and the common electrode 115.

In the display panel 100E, an example is shown in which the buffer layer182 between the pixel electrode 111 and the active layer 113 and thebuffer layer 192 between the pixel electrode 191 and the light-emittinglayer 193 are formed separately. As the buffer layer 182 and the bufferlayer 192, one or both of a hole-injection layer and a hole-transportlayer can be formed, for example.

FIG. 10C is a schematic cross-sectional view of the display panel 100F.The display panel 100F differs from the display panel 100A in that thecommon layers 112 and 114 are not included and the buffer layers 182,184, 192, and 194 are included.

In the display panel 100F, the light-receiving element 110 includes thepixel electrode 111, the buffer layer 182, the active layer 113, thebuffer layer 184, and the common electrode 115. In the display panel100F, the light-emitting element 190 includes the pixel electrode 191,the buffer layer 192, the light-emitting layer 193, the buffer layer194, and the common electrode 115.

Another layer as well as the active layer 113 and the light-emittinglayer 193 can be formed separately when the light-receiving element 110and the light-emitting element 190 are manufactured.

In the example of the display panel 100F, in each of the light-receivingelement 110 and the light-emitting element 190, a common layer is notprovided between the pair of electrodes (the pixel electrode 111 or 191and the common electrode 115). The light-receiving element 110 and thelight-emitting element 190 included in the display panel 100F can bemanufactured in the following manner: the pixel electrode 111 and thepixel electrode 191 are formed over the insulating layer 214 using thesame material in the same step; the buffer layer 182, the active layer113, and the buffer layer 184 are formed over the pixel electrode 111;the buffer layer 192, the light-emitting layer 193, and the buffer layer194 are formed over the pixel electrode 191; and then, the commonelectrode 115 is formed to cover the buffer layer 184, the buffer layer194, and the like.

Note that the manufacturing order of the stacked-layer structure of thebuffer layer 182, the active layer 113, and the buffer layer 184 and thestacked-layer structure of the buffer layer 192, the light-emittinglayer 193, and the buffer layer 194 is not particularly limited. Forexample, after the buffer layer 182, the active layer 113, and thebuffer layer 184 are deposited, the buffer layer 192, the light-emittinglayer 193, and the buffer layer 194 may be formed. In contrast, thebuffer layer 192, the light-emitting layer 193, and the buffer layer 194may be formed before the buffer layer 182, the active layer 113, and thebuffer layer 184 are deposited. Alternatively, the buffer layer 182, thebuffer layer 192, the active layer 113, and the light-emitting layer 193may be deposited in that order, for example.

Configuration Example 2 of Display Panel

More specific configuration examples of the display panel are describedbelow.

Configuration Example 2-1

FIG. 11 is a perspective view of a display panel 200A.

In the display panel 200A, the substrate 151 and the substrate 152 areattached to each other. In FIG. 11 , the substrate 152 is indicated by adashed-dotted line.

The display panel 200A includes a display portion 162, circuits 164, awiring 165, and the like. FIG. 11 shows an example in which anintegrated circuit (IC) 173 and an FPC 172 are mounted on the displaypanel 200A. Thus, the structure shown in FIG. 11 can be regarded as adisplay module including the display panel 200A, the IC, and the FPC.

As the circuits 164, scan line driver circuits can be used.

The wiring 165 has a function of supplying a signal and power to thedisplay portion 162 and the circuits 164. The signal and power are inputto the wiring 165 from the outside through the FPC 172 or from the IC173.

FIG. 11 shows an example in which the IC 173 is provided over thesubstrate 151 by a chip on glass (COG) method, a chip on film (COF)method, or the like. An IC including a scan line driver circuit, asignal line driver circuit, and the like can be used as the IC 173, forexample. Note that the display panel 200A and the display module are notnecessarily provided with an IC. The IC may be mounted on the FPC by aCOF method or the like.

FIG. 12 shows an example of cross sections of part of a region includingthe FPC 172, part of a region including the circuit 164, part of aregion including the display portion 162, and part of a region includingan end portion of the display panel 200A shown in FIG. 11 .

The display panel 200A shown in FIG. 12 includes a transistor 201, atransistor 205, a transistor 206, the light-emitting element 190, thelight-receiving element 110, and the like between the substrate 151 andthe substrate 152.

The substrate 152 and the insulating layer 214 are attached to eachother with the adhesive layer 142. A solid sealing structure, a hollowsealing structure, or the like can be employed to seal thelight-emitting element 190 and the light-receiving element 110. In FIG.12 , a hollow sealing structure is employed in which a space 143surrounded by the substrate 152, the adhesive layer 142, and theinsulating layer 214 is filled with an inert gas (e.g., nitrogen orargon). The adhesive layer 142 may overlap with the light-emittingelement 190. The space 143 surrounded by the substrate 152, the adhesivelayer 142, and the insulating layer 214 may be filled with a resindifferent from that of the adhesive layer 142.

The light-emitting element 190 has a stacked-layer structure in whichthe pixel electrode 191, the common layer 112, the light-emitting layer193, the common layer 114, and the common electrode 115 are stacked inthat order from the insulating layer 214 side. The pixel electrode 191is connected to a conductive layer 222 b included in the transistor 206through an opening provided in the insulating layer 214. The transistor206 has a function of controlling the driving of the light-emittingelement 190. The end portion of the pixel electrode 191 is covered withthe partition 216. The pixel electrode 191 contains a material thatreflects visible light, and the common electrode 115 contains a materialthat transmits visible light.

The light-receiving element 110 has a stacked-layer structure in whichthe pixel electrode 111, the common layer 112, the active layer 113, thecommon layer 114, and the common electrode 115 are stacked in that orderfrom the insulating layer 214 side. The pixel electrode 111 iselectrically connected to the conductive layer 222 b included in thetransistor 205 through an opening provided in the insulating layer 214.The end portion of the pixel electrode 111 is covered with the partition216. The pixel electrode 111 contains a material that reflects visiblelight, and the common electrode 115 contains a material that transmitsvisible light.

Light from the light-emitting element 190 is emitted toward thesubstrate 152. Light is incident on the light-receiving element 110through the substrate 152 and the space 143. For the substrate 152, amaterial having a high visible-light-transmitting property is preferablyused.

The pixel electrode 111 and the pixel electrode 191 can be formed usingthe same material in the same step. The common layer 112, the commonlayer 114, and the common electrode 115 are used in both thelight-receiving element 110 and the light-emitting element 190. Thelight-receiving element 110 and the light-emitting element 190 can havecommon components except the active layer 113 and the light-emittinglayer 193. Thus, the light-receiving element 110 can be incorporated inthe display panel 100A without a significant increase in the number ofmanufacturing steps.

The light-blocking layer BM is provided on the surface of the substrate152 on the substrate 151 side. The light-blocking layer BM has theopening at the position overlapping with the light-receiving element 110and the opening at the position overlapping with the light-emittingelement 190. Providing the light-blocking layer BM can control the rangewhere the light-receiving element 110 detects light. Furthermore,providing the light-blocking layer BM can inhibit light from beingdirectly incident on the light-receiving element 110 from thelight-emitting element 190. Accordingly, a sensor with less noise andhigh sensitivity can be obtained.

The transistor 201, the transistor 205, and the transistor 206 areformed over the substrate 151. These transistors can be formed using thesame material in the same step.

An insulating layer 211, an insulating layer 213, an insulating layer215, and the insulating layer 214 are provided in that order over thesubstrate 151. Part of the insulating layer 211 functions as a gateinsulating layer of each transistor. Part of the insulating layer 213functions as a gate insulating layer of each transistor. The insulatinglayer 215 is provided to cover the transistors. The insulating layer 214is provided to cover the transistors and has a function of aplanarization layer. Note that the number of gate insulating layers andthe number of insulating layers covering the transistors are notlimited, and may each be one, two, or more.

A material through which impurities such as water and hydrogen do noteasily diffuse is preferably used for at least one of the insulatinglayers covering the transistors. This is because such an insulatinglayer can function as a barrier layer. Such a structure can effectivelyinhibit diffusion of impurities into the transistors from the outsideand increase the reliability of a display device.

An inorganic insulating film is preferably used for each of theinsulating layers 211, 213, and 215. As the inorganic insulating film,an inorganic insulating film such as a silicon nitride film, a siliconoxynitride film, a silicon oxide film, a silicon nitride oxide film, analuminum oxide film, or an aluminum nitride film can be used, forexample. Alternatively, a hafnium oxide film, an yttrium oxide film, azirconium oxide film, a gallium oxide film, a tantalum oxide film, amagnesium oxide film, a lanthanum oxide film, a cerium oxide film, aneodymium oxide film, or the like may be used. Alternatively, a stackincluding two or more of the above insulating films may be used.

Here, an organic insulating film often has a lower barrier property thanan inorganic insulating film. Therefore, the organic insulating filmpreferably has an opening in the vicinity of an end portion of thedisplay panel 200A. This can inhibit entry of impurities from the endportion of the display panel 200A through the organic insulating film.Alternatively, the organic insulating film may be formed so that its endportion is positioned on the inner side compared to the end portion ofthe display panel 200A, to prevent the organic insulating film frombeing exposed at the end portion of the display panel 200A.

An organic insulating film is suitable for the insulating layer 214functioning as a planarization layer. Examples of materials that can beused for the organic insulating film include an acrylic resin, apolyimide resin, an epoxy resin, a polyamide resin, a polyimide-amideresin, a siloxane resin, a benzocyclobutene-based resin, a phenol resin,and precursors of these resins.

In a region 228 shown in FIG. 12 , an opening is formed in theinsulating layer 214. This can inhibit entry of impurities into thedisplay portion 162 from the outside through the insulating layer 214even when an organic insulating film is used as the insulating layer214. Consequently, the reliability of the display panel 200A can beincreased.

The transistors 201, 205, and 206 each include a conductive layer 221functioning as a gate, the insulating layer 211 functioning as a gateinsulating layer, a conductive layer 222 a and the conductive layer 222b functioning as a source and a drain, a semiconductor layer 231, theinsulating layer 213 functioning as a gate insulating layer, and aconductive layer 223 functioning as a gate. Here, a plurality of layersobtained by processing the same conductive film are shown with the samehatching pattern. The insulating layer 211 is positioned between theconductive layer 221 and the semiconductor layer 231. The insulatinglayer 213 is positioned between the conductive layer 223 and thesemiconductor layer 231.

There is no particular limitation on the structure of the transistorsincluded in the display panel of this embodiment. For example, a planartransistor, a staggered transistor, or an inverted staggered transistorcan be used. A top-gate transistor or a bottom-gate transistor can beused. Alternatively, gates may be provided above and below asemiconductor layer where a channel is formed.

The transistors 201, 205, and 206 each have a structure in which thesemiconductor layer where a channel is formed is positioned between twogates. The two gates may be connected to each other and supplied withthe same signal to operate the transistor. Alternatively, the thresholdvoltage of the transistor may be controlled by applying a potential forcontrolling the threshold voltage to one of the two gates and apotential for driving to the other of the two gates.

There is no particular limitation on the crystallinity of asemiconductor material used for the transistors, and any of an amorphoussemiconductor, a single crystal semiconductor, and a semiconductorhaving crystallinity other than single crystal (a microcrystallinesemiconductor, a polycrystalline semiconductor, or a semiconductorpartly including crystal regions) may be used. It is preferable to use asingle crystal semiconductor or a semiconductor having crystallinitybecause degradation of transistor characteristics can be inhibited.

The semiconductor layer of the transistor preferably contains a metaloxide (also referred to as an oxide semiconductor). Alternatively, thesemiconductor layer of the transistor may contain silicon. Examples ofsilicon include amorphous silicon and crystalline silicon (e.g.,low-temperature polysilicon and single crystal silicon).

The semiconductor layer preferably contains indium, M (M is one or morekinds selected from gallium, aluminum, silicon, boron, yttrium, tin,copper, vanadium, beryllium, titanium, iron, nickel, germanium,zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum,tungsten, and magnesium), and zinc, for example. Specifically, M ispreferably one or more kinds selected from aluminum, gallium, yttrium,and tin.

It is particularly preferable to use an oxide containing indium (In),gallium (Ga), and zinc (Zn) (also referred to as IGZO) for thesemiconductor layer.

In the case where the semiconductor layer is an In-M-Zn oxide, theatomic ratio of In to M of a sputtering target used for depositing theIn-M-Zn oxide is preferably 1 or more. The atomic ratio of metalelements in such a sputtering target is, for example, In:M:Zn=1:1:1,In:M:Zn=1:1:1.2, In:M:Zn=2:1:3, In:M:Zn=3:1:2, In:M:Zn=4:2:3,In:M:Zn=4:2:4.1, In:M:Zn=5:1:3, In:M:Zn=5:1:6, In:M:Zn=5:1:7,In:M:Zn=5:1:8, In:M:Zn=6:1:6, or In:M:Zn=5:2:5.

A target containing a polycrystalline oxide is preferably used as thesputtering target, which facilitates formation of a semiconductor layerhaving crystallinity. Note that the atomic ratio in the semiconductorlayer to be deposited varies by ±40% from any of the atomic ratios ofthe metal elements contained in the sputtering target. For example, inthe case where the composition of a sputtering target used for thesemiconductor layer is In:Ga:Zn=4:2:4.1 [atomic ratio], the compositionof the semiconductor layer to be deposited is in the neighborhood ofIn:Ga:Zn=4:2:3 [atomic ratio] in some cases.

Note that when the atomic ratio is described as In:Ga:Zn=4:2:3 or asbeing in the neighborhood thereof, the case is included where the atomicproportion of Ga is greater than or equal to 1 and less than or equal to3 and the atomic proportion of Zn is greater than or equal to 2 and lessthan or equal to 4 with the atomic proportion of In being 4. Inaddition, when the atomic ratio is described as In:Ga:Zn=5:1:6 or asbeing in the neighborhood thereof, the case is included where the atomicproportion of Ga is greater than 0.1 and less than or equal to 2 and theatomic proportion of Zn is greater than or equal to 5 and less than orequal to 7 with the atomic proportion of In being 5. Furthermore, whenthe atomic ratio is described as In:Ga:Zn=1:1:1 or as being in theneighborhood thereof, the case is included where the atomic proportionof Ga is greater than 0.1 and less than or equal to 2 and the atomicproportion of Zn is greater than 0.1 and less than or equal to 2 withthe atomic proportion of In being 1.

The transistor included in the circuit 164 and the transistor includedin the display portion 162 may have the same structure or differentstructures. One structure or two or more kinds of structures may beemployed for a plurality of transistors included in the circuit 164.Similarly, one structure or two or more kinds of structures may beemployed for a plurality of transistors included in the display portion162.

A connection portion 204 is provided in a region of the substrate 151where the substrate 152 does not overlap. In the connection portion 204,the wiring 165 is electrically connected to the FPC 172 through aconductive layer 166 and a connection layer 242. On a top surface of theconnection portion 204, the conductive layer 166 obtained by processingthe same conductive film as the pixel electrode 191 is exposed. Thus,the connection portion 204 and the FPC 172 can be electrically connectedto each other through the connection layer 242.

A variety of optical members can be arranged on an outer surface of thesubstrate 152. Examples of the optical members include a polarizingplate, a retardation plate, a light diffusion layer (e.g., a diffusionfilm), an anti-reflective layer, and a light-condensing film.Furthermore, an antistatic film inhibiting the attachment of dust, awater-repellent film suppressing the attachment of stain, a hard coatfilm inhibiting generation of a scratch caused by the use, animpact-absorbing layer, or the like may be provided on the outer surfaceof the substrate 152.

For each of the substrates 151 and 152, glass, quartz, ceramic,sapphire, a resin, or the like can be used. When each of the substrates151 and 152 is formed using a flexible material, the flexibility of thedisplay panel can be increased.

As the adhesive, any of a variety of curable adhesives such as areactive curable adhesive, a thermosetting curable adhesive, ananaerobic adhesive, and a photocurable adhesive such as an ultravioletcurable adhesive can be used. Examples of these adhesives include anepoxy resin, an acrylic resin, a silicone resin, a phenol resin, apolyimide resin, an imide resin, a polyvinyl chloride (PVC) resin, apolyvinyl butyral (PVB) resin, and an ethylene vinyl acetate (EVA)resin. In particular, a material with low moisture permeability, such asan epoxy resin, is preferred. A two-component-mixture-type resin may beused. An adhesive sheet or the like may be used.

As the connection layer 242, an anisotropic conductive film (ACF), ananisotropic conductive paste (ACP), or the like can be used.

The light-emitting element 190 may be a top emission, bottom emission,or dual emission light-emitting element, or the like. A conductive filmthat transmits visible light is used as the electrode through whichlight is extracted. A conductive film that reflects visible light ispreferably used as the electrode through which light is not extracted.

The light-emitting element 190 includes at least the light-emittinglayer 193. In addition to the light-emitting layer 193, thelight-emitting element 190 may further include a layer containing any ofa substance with a high hole-injection property, a substance with a highhole-transport property, a hole-blocking material, a substance with ahigh electron-transport property, a substance with a highelectron-injection property, a substance with a bipolar property (asubstance with a high electron- and hole-transport property), and thelike. For example, the common layer 112 preferably includes one or bothof a hole-injection layer and a hole-transport layer. For example, thecommon layer 114 preferably includes one or both of anelectron-transport layer and an electron-injection layer.

Either a low-molecular compound or a high-molecular compound can be usedfor the common layer 112, the light-emitting layer 193, and the commonlayer 114, and an inorganic compound may also be contained. The layersincluded in the common layer 112, the light-emitting layer 193, and thecommon layer 114 can be formed by any of the following methods, forexample: an evaporation method (including a vacuum evaporation method),a transfer method, a printing method, an inkjet method, and a coatingmethod.

The light-emitting layer 193 may contain an inorganic compound such asquantum dots.

The active layer 113 of the light-receiving element 110 contains asemiconductor. Examples of the semiconductor include an inorganicsemiconductor such as silicon and an organic semiconductor including anorganic compound. This embodiment shows an example in which an organicsemiconductor is used as the semiconductor contained in the activelayer. The use of an organic semiconductor is preferable because thelight-emitting layer 193 of the light-emitting element 190 and theactive layer 113 of the light-receiving element 110 can be formed by thesame method (e.g., a vacuum evaporation method) and thus the samemanufacturing apparatus can be used.

Examples of an n-type semiconductor material contained in the activelayer 113 include electron-accepting organic semiconductor materialssuch as fullerene (e.g., C₆₀ and C₇₀) and derivatives thereof. Examplesof a p-type semiconductor material contained in the active layer 113include electron-donating organic semiconductor materials such ascopper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP),and zinc phthalocyanine (ZnPc).

For example, the active layer 113 is preferably formed by co-evaporationof an n-type semiconductor and a p-type semiconductor.

As materials of a gate, a source, and a drain of a transistor, andconductive layers functioning as wirings and electrodes included in thedisplay panel, any of metals such as aluminum, titanium, chromium,nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, andtungsten, or an alloy containing any of these metals as its maincomponent can be used. A single-layer structure or a stacked-layerstructure including a film containing any of these materials can beused.

As a light-transmitting conductive material, a conductive oxide such asindium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zincoxide containing gallium, or graphene can be used. Alternatively, ametal material such as gold, silver, platinum, magnesium, nickel,tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, ortitanium, or an alloy material containing any of these metal materialscan be used. Alternatively, a nitride of the metal material (e.g.,titanium nitride) or the like may be used. Note that in the case ofusing the metal material or the alloy material (or the nitride thereof),the thickness is preferably set small enough to transmit light.Alternatively, a stacked film of any of the above materials can be usedfor the conductive layers. For example, a stacked film of indium tinoxide and an alloy of silver and magnesium is preferably used becauseconductivity can be increased. These materials can also be used forconductive layers such as wirings and electrodes included in the displaypanel, and conductive layers (e.g., a conductive layer functioning as apixel electrode or a common electrode) included in a display element.

Examples of insulating materials that can be used for the insulatinglayers include a resin such as an acrylic resin and an epoxy resin, andan inorganic insulating material such as silicon oxide, siliconoxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

Configuration Example 2-2

FIG. 13A is a cross-sectional view of a display panel 200B. The displaypanel 200B differs from the display panel 200A mainly in that the lens149 and the protective layer 195 are provided.

Providing the protective layer 195 covering the light-receiving element110 and the light-emitting element 190 can inhibit diffusion ofimpurities such as water into the light-receiving element 110 and thelight-emitting element 190, so that the reliability of thelight-receiving element 110 and the light-emitting element 190 can beincreased.

In the region 228 in the vicinity of an end portion of the display panel200B, the insulating layer 215 and the protective layer 195 arepreferably in contact with each other through an opening in theinsulating layer 214. In particular, the inorganic insulating filmincluded in the insulating layer 215 and an inorganic insulating filmincluded in the protective layer 195 are preferably in contact with eachother. Thus, diffusion of impurities from the outside into the displayportion 162 through an organic insulating film can be inhibited.Accordingly, the reliability of the display panel 200B can be increased.

FIG. 13B shows an example in which the protective layer 195 has athree-layer structure. In FIG. 13B, the protective layer 195 includes aninorganic insulating layer 195 a over the common electrode 115, anorganic insulating layer 195 b over the inorganic insulating layer 195a, and an inorganic insulating layer 195 c over the organic insulatinglayer 195 b.

An end portion of the inorganic insulating layer 195 a and an endportion of the inorganic insulating layer 195 c extend beyond an endportion of the organic insulating layer 195 b and are in contact witheach other. The inorganic insulating layer 195 a is in contact with theinsulating layer 215 (inorganic insulating layer) through the opening inthe insulating layer 214 (organic insulating layer). Accordingly, thelight-receiving element 110 and the light-emitting element 190 can besurrounded by the insulating layer 215 and the protective layer 195, sothat the reliability of the light-receiving element 110 and thelight-emitting element 190 can be increased.

As described above, the protective layer 195 may have a stacked-layerstructure of an organic insulating film and an inorganic insulatingfilm. In that case, an end portion of the inorganic insulating filmpreferably extends beyond an end portion of the organic insulating film.

The lens 149 is provided on the surface of the substrate 152 on thesubstrate 151 side. The lens 149 has the convex surface on the substrate151 side. It is preferable that the light-receiving region of thelight-receiving element 110 overlap with the lens 149 and do not overlapwith the light-emitting layer 193. Thus, the sensitivity and accuracy ofthe sensor using the light-receiving element 110 can be increased.

The lens 149 preferably has a refractive index of higher than or equalto 1.3 and lower than or equal to 2.5 with respect to the wavelength oflight received by the light-receiving element 110. The lens 149 can beformed using at least one of an inorganic material and an organicmaterial. For example, a material containing a resin can be used for thelens 149. Moreover, a material containing at least one of an oxide and asulfide can be used for the lens 149.

Specifically, a resin containing chlorine, bromine, or iodine, a resincontaining a heavy metal atom, a resin having an aromatic ring, a resincontaining sulfur, or the like can be used for the lens 149.Alternatively, a material containing a resin and nanoparticles of amaterial having a higher refractive index than the resin can be used forthe lens 149. Titanium oxide, zirconium oxide, or the like can be usedfor the nanoparticles.

Alternatively, cerium oxide, hafnium oxide, lanthanum oxide, magnesiumoxide, niobium oxide, tantalum oxide, titanium oxide, yttrium oxide,zinc oxide, an oxide containing indium and tin, an oxide containingindium, gallium, and zinc, or the like can be used for the lens 149.Alternatively, zinc sulfide or the like can be used for the lens 149.

In the display panel 200B, the protective layer 195 and the substrate152 are attached to each other with the adhesive layer 142. The adhesivelayer 142 is provided to overlap with the light-receiving element 110and the light-emitting element 190, and the display panel 200B has asolid sealing structure.

Configuration Example 2-3

FIG. 14A is a cross-sectional view of a display panel 200C. The displaypanel 200C differs from the display panel 200B mainly in the transistorstructure and including neither the light-blocking layer BM nor the lens149.

The display panel 200C includes a transistor 208, a transistor 209, anda transistor 210 over the substrate 151.

The transistors 208, 209, and 210 each include the conductive layer 221functioning as a gate, the insulating layer 211 functioning as a gateinsulating layer, a semiconductor layer including a channel formationregion 231 i and a pair of low-resistance regions 231 n, the conductivelayer 222 a connected to one of the pair of low-resistance regions 231n, the conductive layer 222 b connected to the other of the pair oflow-resistance regions 231 n, an insulating layer 225 functioning as agate insulating layer, the conductive layer 223 functioning as a gate,and the insulating layer 215 covering the conductive layer 223. Theinsulating layer 211 is positioned between the conductive layer 221 andthe channel formation region 231 i. The insulating layer 225 ispositioned between the conductive layer 223 and the channel formationregion 231 i.

The conductive layer 222 a and the conductive layer 222 b are connectedto the low-resistance regions 231 n through openings provided in theinsulating layer 225 and the insulating layer 215. One of the conductivelayer 222 a and the conductive layer 222 b functions as a source, andthe other of the conductive layer 222 a and the conductive layer 222 bfunctions as a drain.

The pixel electrode 191 of the light-emitting element 190 iselectrically connected to one of the pair of low-resistance regions 231n of the transistor 208 through the conductive layer 222 b.

The pixel electrode 111 of the light-receiving element 110 iselectrically connected to the other of the pair of low-resistanceregions 231 n of the transistor 209 through the conductive layer 222 b.

FIG. 14A shows an example in which the insulating layer 225 covers a topsurface and a side surface of the semiconductor layer. FIG. 14B shows anexample of a transistor 202 in which the insulating layer 225 overlapswith the channel formation region 231 i of the semiconductor layer 231and does not overlap with the low-resistance regions 231 n. Thestructure shown in FIG. 14B can be obtained by processing the insulatinglayer 225 using the conductive layer 223 as a mask, for example. In FIG.14B, the insulating layer 215 is provided to cover the insulating layer225 and the conductive layer 223, and the conductive layer 222 a and theconductive layer 222 b are connected to the low-resistance regions 231 nthrough openings in the insulating layer 215. Furthermore, an insulatinglayer 218 covering the transistor may be provided.

Configuration Example 2-4

FIG. 15 is a cross-sectional view of a display panel 200D. The displaypanel 200D differs from the display panel 200C mainly in the substratestructure.

The display panel 200D includes neither the substrate 151 nor thesubstrate 152 and includes the substrate 153, the substrate 154, theadhesive layer 155, and the insulating layer 212.

The substrate 153 and the insulating layer 212 are attached to eachother with the adhesive layer 155. The substrate 154 and the protectivelayer 195 are attached to each other with the adhesive layer 142.

The display panel 200D is formed in such a manner that the insulatinglayer 212, the transistor 208, the transistor 209, the light-receivingelement 110, the light-emitting element 190, and the like that areformed over a formation substrate are transferred onto the substrate153. The substrate 153 and the substrate 154 are preferably flexible.Accordingly, the display panel 200D can be highly flexible.

The inorganic insulating film that can be used for the insulating layer211, the insulating layer 213, and the insulating layer 215 can be usedfor the insulating layer 212. Alternatively, a stacked film of anorganic insulating film and an inorganic insulating film may be used forthe insulating layer 212. In that case, a film on the transistor 209side is preferably an inorganic insulating film.

The above is the description of the configuration examples of thedisplay panel.

[Metal Oxide]

A metal oxide that can be used for the semiconductor layer is describedbelow.

Note that in this specification and the like, a metal oxide containingnitrogen is also referred to as a metal oxide in some cases. Inaddition, a metal oxide containing nitrogen may be referred to as ametal oxynitride. For example, a metal oxide containing nitrogen, suchas zinc oxynitride (ZnON), may be used for the semiconductor layer.

Note that the terms “CAAC (c-axis aligned crystal)” and “CAC(cloud-aligned composite)” might appear in this specification and thelike. CAAC refers to an example of a crystal structure, and CAC refersto an example of a function or a material composition.

For example, a cloud-aligned composite oxide semiconductor (CAC-OS) canbe used for the semiconductor layer.

A CAC-OS or a CAC-metal oxide has a conducting function in part of thematerial and has an insulating function in another part of the material;as a whole, the CAC-OS or the CAC-metal oxide has a function of asemiconductor. Note that in the case where the CAC-OS or the CAC-metaloxide is used in a semiconductor layer of a transistor, the conductingfunction is a function that allows electrons (or holes) serving ascarriers to flow, and the insulating function is a function that doesnot allow electrons serving as carriers to flow. By the complementaryaction of the conducting function and the insulating function, aswitching function (On/Off function) can be given to the CAC-OS or theCAC-metal oxide. In the CAC-OS or the CAC-metal oxide, separation of thefunctions can maximize each function.

Furthermore, the CAC-OS or the CAC-metal oxide includes conductiveregions and insulating regions. The conductive regions have the aboveconducting function, and the insulating regions have the aboveinsulating function. Furthermore, in some cases, the conductive regionsand the insulating regions in the material are separated at thenanoparticle level. Furthermore, in some cases, the conductive regionsand the insulating regions are unevenly distributed in the material.Furthermore, the conductive regions are observed to be coupled in acloud-like manner with their boundaries blurred, in some cases.

Furthermore, in the CAC-OS or the CAC-metal oxide, the conductiveregions and the insulating regions each have a size greater than orequal to 0.5 nm and less than or equal to 10 nm, preferably greater thanor equal to 0.5 nm and less than or equal to 3 nm, and are dispersed inthe material, in some cases.

Furthermore, the CAC-OS or the CAC-metal oxide includes componentshaving different bandgaps. For example, the CAC-OS or the CAC-metaloxide includes a component having a wide gap due to the insulatingregion and a component having a narrow gap due to the conductive region.In the case of the structure, when carriers flow, carriers mainly flowthrough the component having a narrow gap. Furthermore, the componenthaving a narrow gap complements the component having a wide gap, andcarriers also flow through the component having a wide gap inconjunction with the component having a narrow gap. Therefore, in thecase where the CAC-OS or the CAC-metal oxide is used for the channelformation region of the transistor, high current drive capability in anon state of the transistor, that is, high on-state current and highfield-effect mobility can be obtained.

In other words, the CAC-OS or the CAC-metal oxide can also be referredto as a matrix composite or a metal matrix composite.

Oxide semiconductors (metal oxides) are classified into a single crystaloxide semiconductor and a non-single crystal oxide semiconductor.Examples of a non-single crystal oxide semiconductor include a CAAC-OS(c-axis aligned crystalline oxide semiconductor), a polycrystallineoxide semiconductor, an nc-OS (nanocrystalline oxide semiconductor), anamorphous-like oxide semiconductor (a-like OS), and an amorphous oxidesemiconductor.

The CAAC-OS has c-axis alignment, a plurality of nanocrystals areconnected in the a-b plane direction, and its crystal structure hasdistortion. Note that the distortion refers to a portion where thedirection of lattice arrangement changes between a region with regularlattice arrangement and another region with regular lattice arrangementin a region where the plurality of nanocrystals are connected.

The nanocrystal is basically a hexagon but is not always a regularhexagon and is a non-regular hexagon in some cases. Furthermore,pentagonal lattice arrangement, heptagonal lattice arrangement, and thelike are included in the distortion in some cases. Note that it isdifficult to observe a clear crystal grain boundary (also referred to asgrain boundary) even in the vicinity of distortion in the CAAC-OS. Thatis, formation of a crystal grain boundary is inhibited by the distortionof lattice arrangement. This is because the CAAC-OS can toleratedistortion owing to the low density of oxygen atom arrangement in thea-b plane direction, a change in interatomic bond distance byreplacement of a metal element, and the like.

Furthermore, the CAAC-OS tends to have a layered crystal structure (alsoreferred to as a layered structure) in which a layer containing indiumand oxygen (hereinafter referred to as an In layer) and a layercontaining the element M, zinc, and oxygen (hereinafter referred to asan (M,Zn) layer) are stacked. Note that indium and the element M can bereplaced with each other, and when the element M in the (M,Zn) layer isreplaced with indium, the layer can also be referred to as an (In,M,Zn)layer. Furthermore, when indium in the In layer is replaced with theelement M, the layer can be referred to as an (In,M) layer.

The CAAC-OS is a metal oxide with high crystallinity. Meanwhile, in theCAAC-OS, it can be said that a reduction in electron mobility due to thecrystal grain boundary is less likely to occur because it is difficultto observe a clear crystal grain boundary. Furthermore, the mixing ofimpurities, formation of defects, or the like might decrease thecrystallinity of the metal oxide; thus, it can also be said that theCAAC-OS is a metal oxide having small amounts of impurities and defects(e.g., oxygen vacancies (V_(O))). Thus, a metal oxide including aCAAC-OS is physically stable. Therefore, the metal oxide including aCAAC-OS is resistant to heat and has high reliability.

In the nc-OS, a microscopic region (for example, a region with a sizegreater than or equal to 1 nm and less than or equal to 10 nm, inparticular, a region with a size greater than or equal to 1 nm and lessthan or equal to 3 nm) has periodic atomic arrangement. Furthermore,there is no regularity of crystal orientation between differentnanocrystals in the nc-OS. Thus, the orientation in the whole film isnot observed. Accordingly, the nc-OS cannot be distinguished from ana-like OS or an amorphous oxide semiconductor, depending on the analysismethod.

Note that indium-gallium-zinc oxide (hereinafter referred to as IGZO)that is a kind of metal oxide containing indium, gallium, and zinc has astable structure in some cases when formed of the nanocrystals. Inparticular, IGZO crystals tend not to grow in the air and thus, a stablestructure is obtained in some cases when IGZO is formed of smallercrystals (e.g., the nanocrystals) rather than larger crystals (here,crystals with a size of several millimeters or several centimeters).

The a-like OS is a metal oxide that has a structure between those of thenc-OS and the amorphous oxide semiconductor. The a-like OS includes avoid or a low-density region. That is, the a-like OS has lowercrystallinity than the nc-OS and the CAAC-OS.

An oxide semiconductor (a metal oxide) has various structures withdifferent properties. Two or more kinds of the amorphous oxidesemiconductor, the polycrystalline oxide semiconductor, the a-like OS,the nc-OS, and the CAAC-OS may be included in an oxide semiconductor ofone embodiment of the present invention.

A metal oxide film that functions as a semiconductor layer can bedeposited using either or both of an inert gas and an oxygen gas. Notethat there is no particular limitation on the flow rate ratio of oxygen(the partial pressure of oxygen) at the time of deposition of the metaloxide film. However, to obtain a transistor having high field-effectmobility, the flow rate ratio of oxygen (the partial pressure of oxygen)at the time of deposition of the metal oxide film is preferably higherthan or equal to 0% and lower than or equal to 30%, further preferablyhigher than or equal to 5% and lower than or equal to 30%, still furtherpreferably higher than or equal to 7% and lower than or equal to 15%.

The energy gap of the metal oxide is preferably greater than or equal to2 eV, further preferably greater than or equal to 2.5 eV, still furtherpreferably greater than or equal to 3 eV. With the use of a metal oxidehaving such a wide energy gap, the off-state current of the transistorcan be reduced.

The substrate temperature during the deposition of the metal oxide filmis preferably lower than or equal to 350° C., further preferably higherthan or equal to room temperature and lower than or equal to 200° C.,still further preferably higher than or equal to room temperature andlower than or equal to 130° C. The substrate temperature during thedeposition of the metal oxide film is preferably room temperaturebecause productivity can be increased.

The metal oxide film can be formed by a sputtering method.Alternatively, a PLD method, a PECVD method, a thermal CVD method, anALD method, a vacuum evaporation method, or the like may be used.

The above is the description of the metal oxide.

At least part of this embodiment can be implemented in combination withany of the other embodiments described in this specification asappropriate.

Embodiment 3

In this embodiment, a display panel that can be used in the system ofone embodiment of the present invention will be described with referenceto FIG. 16A and FIG. 16B.

The display panel of one embodiment of the present invention includesfirst pixel circuits including a light-receiving element and secondpixel circuits including a light-emitting element. The first pixelcircuits and the second pixel circuits are each arranged in a matrix.

FIG. 16A shows an example of the first pixel circuit including alight-receiving element, and FIG. 16B shows an example of the secondpixel circuit including a light-emitting element.

A pixel circuit PIX1 illustrated in FIG. 16A includes a light-receivingelement PD, a transistor M1, a transistor M2, a transistor M3, atransistor M4, and a capacitor C1. Here, a photodiode is used as anexample of the light-receiving element PD.

A cathode of the light-receiving element PD is electrically connected toa wiring V1 and an anode is electrically connected to one of a sourceand a drain of the transistor M1. A gate of the transistor M1 iselectrically connected to a wiring TX, and the other of the source andthe drain is electrically connected to one electrode of the capacitorC1, one of a source and a drain of the transistor M2, and a gate of thetransistor M3. A gate of the transistor M2 is electrically connected toa wiring RES, and the other of the source and the drain is electricallyconnected to a wiring V2. One of a source and a drain of the transistorM3 is electrically connected to a wiring V3, and the other of the sourceand the drain is electrically connected to one of a source and a drainof the transistor M4. A gate of the transistor M4 is electricallyconnected to a wiring SE, and the other of the source and the drain iselectrically connected to a wiring OUT1.

A constant potential is supplied to the wiring V1, the wiring V2, andthe wiring V3. When the light-receiving element PD is driven with areverse bias, the wiring V2 is supplied with a potential lower than thepotential of the wiring V1. The transistor M2 is controlled by a signalsupplied to the wiring RES and has a function of resetting the potentialof a node connected to the gate of the transistor M3 to a potentialsupplied to the wiring V2. The transistor M1 is controlled by a signalsupplied to the wiring TX and has a function of controlling the timingat which the potential of the node changes, in accordance with a currentflowing through the light-receiving element PD. The transistor M3functions as an amplifier transistor for outputting a signalcorresponding to the potential of the node. The transistor M4 iscontrolled by a signal supplied to the wiring SE and functions as aselection transistor for reading an output corresponding to thepotential of the node by an external circuit connected to the wiringOUT1.

A pixel circuit PIX2 illustrated in FIG. 16B includes a light-emittingelement EL, a transistor M5, a transistor M6, a transistor M7, and acapacitor C2. Here, a light-emitting diode is used as an example of thelight-emitting element EL. In particular, an organic EL element ispreferably used as the light-emitting element EL.

A gate of the transistor M5 is electrically connected to a wiring VG,one of a source and a drain is electrically connected to a wiring VS,and the other of the source and the drain is electrically connected toone electrode of the capacitor C2 and a gate of the transistor M6. Oneof a source and a drain of the transistor M6 is electrically connectedto a wiring V4, and the other is electrically connected to an anode ofthe light-emitting element EL and one of a source and a drain of thetransistor M7. A gate of the transistor M7 is electrically connected toa wiring MS, and the other of the source and the drain is electricallyconnected to a wiring OUT2. A cathode of the light-emitting element ELis electrically connected to a wiring V5.

A constant potential is supplied to the wiring V4 and the wiring V5. Inthe light-emitting element EL, the anode side can have a high potentialand the cathode side can have a lower potential than the anode side. Thetransistor M5 is controlled by a signal supplied to the wiring VG andfunctions as a selection transistor for controlling a selection state ofthe pixel circuit PIX2. The transistor M6 functions as a drivingtransistor that controls a current flowing through the light-emittingelement EL in accordance with a potential supplied to the gate. When thetransistor M5 is in an on state, a potential supplied to the wiring VSis supplied to the gate of the transistor M6, and the luminance of thelight-emitting element EL can be controlled in accordance with thepotential. The transistor M7 is controlled by a signal supplied to thewiring MS and has a function of outputting a potential between thetransistor M6 and the light-emitting element EL to the outside throughthe wiring OUT2.

Note that in the display panel of this embodiment, the light-emittingelement may be made to emit light in a pulsed manner so as to display animage. A reduction in the driving time of the light-emitting element canreduce power consumption of the display panel and suppress heatgeneration. An organic EL element is particularly preferable because ofits favorable frequency characteristics. The frequency can be 1 kHz to100 MHz, for example.

Here, a transistor in which a metal oxide (an oxide semiconductor) isused in a semiconductor layer where a channel is formed is preferablyused as the transistor M1, the transistor M2, the transistor M3, and thetransistor M4 included in the pixel circuit PIX1 and the transistor M5,the transistor M6, and the transistor M7 included in the pixel circuitPIX2.

A transistor using a metal oxide having a wider band gap and a lowercarrier density than silicon can achieve an extremely low off-statecurrent. Such a low off-state current enables retention of chargesaccumulated in a capacitor that is connected in series with thetransistor for a long time. Therefore, it is particularly preferable touse a transistor including an oxide semiconductor as the transistor M1,the transistor M2, and the transistor M5 each of which is connected inseries with the capacitor C1 or the capacitor C2. Moreover, the use oftransistors including an oxide semiconductor as the other transistorscan reduce the manufacturing cost.

Alternatively, transistors using silicon as a semiconductor in which achannel is formed can be used as the transistor M1 to the transistor M7.In particular, the use of silicon with high crystallinity, such assingle crystal silicon or polycrystalline silicon, is preferable becausehigh field-effect mobility is achieved and higher-speed operation ispossible.

Alternatively, a transistor including an oxide semiconductor may be usedas at least one of the transistor M1 to the transistor M7, andtransistors including silicon may be used as the other transistors.

Although the transistors are illustrated as n-channel transistors inFIG. 16A and FIG. 16B, p-channel transistors can alternatively be used.

The transistors included in the pixel circuit PIX1 and the transistorsincluded in the pixel circuit PIX2 are preferably formed side by sideover the same substrate. It is particularly preferable that thetransistors included in the pixel circuit PIX1 and the transistorsincluded in the pixel circuit PIX2 be periodically arranged in oneregion.

One or more layers including one or both of the transistor and thecapacitor are preferably provided to overlap with the light-receivingelement PD or the light-emitting element EL. Thus, the effective area ofeach pixel circuit can be reduced, and a high-definition light-receivingportion or display portion can be achieved.

At least part of this embodiment can be implemented in combination withany of the other embodiments described in this specification asappropriate.

REFERENCE NUMERALS

-   10: display system, 11: display device, 12, 12 a, 12 b:    light-emitting apparatus, 15, 15 a, 15 b: light-receiving module,    16: control device, 20: display panel, 21: display unit, 22: pixel,    23, 23G, 23R, 23B: display element, 24: light-receiving element, 25,    26: driver circuit, 30: light-receiving unit, 31: light-receiving    element, 41: control unit, 42, 42 a, 42 b, 43, 43 a, 43 b: driver    unit, 51, 52: switch, 53, 54: light-emitting element, 55, 57: driver    unit, 56: signal generation unit, 58, 59, 59 a, 59 b: irradiation    region, 60, 60 a, 60 b: user, 61, 62, 63, 64, 66 a, 66 b, 67 a, 67    b, 68: object, 65: locus, 69 a, 69 b, 69 c, 69 d: icon

This application is based on Japanese Patent Application Serial No.2019-006581 filed on Jan. 18, 2019, the entire contents of which arehereby incorporated herein by reference.

1. A display system comprising a display panel and a light-emittingapparatus, wherein the display panel comprises a display element, afirst light-receiving element, a second light-receiving element, a firsttransistor and a second transistor, wherein the light-emitting apparatuscomprises a first input means, a second input means, a firstlight-emitting element, a second light-emitting element, a driver unit,and an oscillator device, wherein the display element comprises a firstpixel electrode, a first common layer, a light-emitting layer, and acommon electrode, wherein the first light-receiving element comprises asecond pixel electrode, the first common layer, an active layer, and thecommon electrode, wherein a source or a drain of the first transistor iselectrically connected to the first pixel electrode, wherein a source ora drain of the second transistor is electrically connected to the secondpixel electrode, wherein the first light-emitting element comprises alaser light source exhibiting visible light, wherein the secondlight-emitting element comprises a light source exhibiting infraredlight, wherein the driver unit is configured to control a light emissionstate of the first light-emitting element in accordance with an input tothe first input means, wherein the oscillator device is configured tocontrol a light emission state of the second light-emitting element inaccordance with an input to the second input means, wherein a firstsystem comprises the first light-emitting element, the driver unit, andthe first input means, wherein a second system comprises the secondlight-emitting element, the oscillator device and the second inputmeans, wherein the first system and the second system are independentfrom each other, wherein the first light-receiving element is configuredto receive the visible light emitted by the first light-emitting elementand convert the visible light into a first electric signal, and whereinthe second light-receiving element is configured to receive the infraredlight emitted by the second light-emitting element and convert theinfrared light into a second electric signal.
 2. The display systemaccording to claim 1, wherein the display element comprises a portionoverlapping with the first transistor, and wherein the firstlight-receiving element comprises a portion overlapping with the secondtransistor.
 3. The display system according to claim 1, wherein thefirst transistor and the second transistor are over the same plane. 4.The display system according to claim 1, wherein the first transistorand the second transistor each comprise a metal oxide in a channelformation region, wherein the metal oxide comprises In, Zn, and M, andwherein M is Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf.
 5. The displaysystem according to claim 1, wherein the driver unit is configured tocontrol the light emission state by controlling light emission ornon-light emission of the first light-emitting element in accordancewith the operation of the first input means.
 6. A display devicecomprising a display element, a first light-receiving element, a secondlight-receiving element receiving infrared light, a first transistor anda second transistor, wherein the display element comprises a first pixelelectrode, a first common layer, a light-emitting layer, and a commonelectrode, wherein the first light-receiving element comprises a secondpixel electrode, the first common layer, an active layer, and the commonelectrode, wherein the first common layer is provided over the firstpixel electrode and the second pixel electrode, wherein thelight-emitting layer and the active layer are in contact with a topsurface of the first common layer, wherein a source or a drain of thefirst transistor is electrically connected to the first pixel electrode,and wherein a source or a drain of the second transistor is electricallyconnected to the second pixel electrode.
 7. The display device accordingto claim 6, wherein the light-emitting layer and the active layer eachcomprise a different organic compound, wherein the first pixel electrodeand the second pixel electrode are over the same plane, and wherein thecommon electrode comprises a portion overlapping with the first pixelelectrode with the light-emitting layer therebetween, and a portionoverlapping with the second pixel electrode with the active layertherebetween.
 8. The display device according to claim 6, wherein thedisplay element and the first light-receiving element comprise a secondcommon layer, wherein the second common layer comprises a portionbetween the first pixel electrode and the common electrode, and aportion between the second pixel electrode and the common electrode. 9.The display device according to claim 6, wherein the display elementcomprises a portion overlapping with the first transistor, and whereinthe first light-receiving element comprises a portion overlapping withthe second transistor.
 10. The display device according to claim 6,wherein the first transistor and the second transistor are over the sameplane.
 11. The display device according to claim 6, wherein the firsttransistor and the second transistor each comprise a metal oxide in achannel formation region, wherein the metal oxide comprises In, Zn, andM, and wherein M is Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf.
 12. Thedisplay device according to claim 6, wherein the display device isconfigured to display an image and obtain positional information on aportion irradiated with the visible light, and wherein thelight-receiving unit is configured to receive invisible light.